diff --git a/Gemfile b/Gemfile
index 6652d1e35b2..723cfd8b058 100644
--- a/Gemfile
+++ b/Gemfile
@@ -46,6 +46,9 @@ gem "grape-entity", "~> 0.2.0"
 # based on human-friendly examples
 gem "stamp"
 
+# Enumeration fields
+gem 'enumerize'
+
 # Pagination
 gem "kaminari", "~> 0.14.1"
 
@@ -113,6 +116,7 @@ group :assets do
   gem 'bootstrap-sass',   "2.2.1.1"
   gem "font-awesome-sass-rails", "~> 3.0.0"
   gem "gemoji", "~> 1.2.1", require: 'emoji/railtie'
+  gem "gon"
 end
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index 7a7153fcd2d..9ee413d4738 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -146,6 +146,8 @@ GEM
     email_spec (1.4.0)
       launchy (~> 2.1)
       mail (~> 2.2)
+    enumerize (0.5.1)
+      activesupport (>= 3.2)
     erubis (2.7.0)
     escape_utils (0.2.4)
     eventmachine (1.0.0)
@@ -184,10 +186,13 @@ GEM
       pyu-ruby-sasl (~> 0.0.3.1)
       rubyntlm (~> 0.1.1)
     gitlab_yaml_db (1.0.0)
+    gon (4.0.2)
     grape (0.3.1)
+      actionpack (>= 2.3.0)
       activesupport
       grape-entity (~> 0.2.0)
       hashie (~> 1.2)
+      json
       multi_json (>= 1.3.2)
       multi_xml
       rack
@@ -473,6 +478,7 @@ DEPENDENCIES
   devise (~> 2.1.0)
   draper (~> 0.18.0)
   email_spec
+  enumerize
   factory_girl_rails
   ffaker
   font-awesome-sass-rails (~> 3.0.0)
@@ -484,6 +490,7 @@ DEPENDENCIES
   gitlab_meta (= 5.0)
   gitlab_omniauth-ldap (= 1.0.2)
   gitlab_yaml_db (= 1.0.0)
+  gon
   grack!
   grape (~> 0.3.1)
   grape-entity (~> 0.2.0)
diff --git a/app/assets/javascripts/projects.js.coffee b/app/assets/javascripts/projects.js.coffee
index d03a487c453..24106c61b75 100644
--- a/app/assets/javascripts/projects.js.coffee
+++ b/app/assets/javascripts/projects.js.coffee
@@ -18,3 +18,18 @@ $ ->
   # Ref switcher
   $('.project-refs-select').on 'change', ->
     $(@).parents('form').submit()
+
+  $('#project_issues_enabled').change ->
+    if ($(this).is(':checked') == true)
+      $('#project_issues_tracker').removeAttr('disabled')
+    else
+      $('#project_issues_tracker').attr('disabled', 'disabled')
+
+    $('#project_issues_tracker').change()
+
+  $('#project_issues_tracker').change ->
+    if ($(this).val() == gon.default_issues_tracker || $(this).is(':disabled'))
+      $('#project_issues_tracker_id').attr('disabled', 'disabled')
+    else
+      $('#project_issues_tracker_id').removeAttr('disabled')
+
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 1f211bac9c2..5b886227bc9 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -5,6 +5,7 @@ class ApplicationController < ActionController::Base
   before_filter :add_abilities
   before_filter :dev_tools if Rails.env == 'development'
   before_filter :default_headers
+  before_filter :add_gon_variables
 
   protect_from_forgery
 
@@ -148,4 +149,8 @@ class ApplicationController < ActionController::Base
     headers['X-Frame-Options'] = 'DENY'
     headers['X-XSS-Protection'] = '1; mode=block'
   end
+
+  def add_gon_variables
+    gon.default_issues_tracker = Project.issues_tracker.default_value
+  end
 end
diff --git a/app/helpers/issues_helper.rb b/app/helpers/issues_helper.rb
index ed7e3e869c0..83215180492 100644
--- a/app/helpers/issues_helper.rb
+++ b/app/helpers/issues_helper.rb
@@ -40,4 +40,39 @@ module IssuesHelper
   def issues_active_milestones
     @project.milestones.active.order("id desc").all
   end
+
+  def url_for_project_issues
+    return "" if @project.nil?
+
+    if @project.used_default_issues_tracker?
+      project_issues_filter_path(@project) 
+    else
+      url = Settings[:issues_tracker][@project.issues_tracker]["project_url"]
+      url.gsub(':project_id', @project.id.to_s)
+         .gsub(':issues_tracker_id', @project.issues_tracker_id.to_s)
+    end
+  end
+
+  def url_for_issue(issue_id)
+    return "" if @project.nil?
+
+    if @project.used_default_issues_tracker?
+      url = project_issue_url project_id: @project, id: issue_id
+    else
+      url = Settings[:issues_tracker][@project.issues_tracker]["issues_url"]
+      url.gsub(':id', issue_id.to_s)
+        .gsub(':project_id', @project.id.to_s)
+        .gsub(':issues_tracker_id', @project.issues_tracker_id.to_s)
+    end
+  end
+
+  def title_for_issue(issue_id)
+    return "" if @project.nil?
+
+    if @project.used_default_issues_tracker? && issue = @project.issues.where(id: issue_id).first
+      issue.title
+    else
+      ""
+    end
+  end
 end
diff --git a/app/models/project.rb b/app/models/project.rb
index 6ff2a3698df..12f7e45496b 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -11,6 +11,7 @@
 #  creator_id             :integer
 #  default_branch         :string(255)
 #  issues_enabled         :boolean          default(TRUE), not null
+#  issues_tracker         :string           not null
 #  wall_enabled           :boolean          default(TRUE), not null
 #  merge_requests_enabled :boolean          default(TRUE), not null
 #  wiki_enabled           :boolean          default(TRUE), not null
@@ -22,11 +23,12 @@ require "grit"
 
 class Project < ActiveRecord::Base
   include Gitolited
+  extend Enumerize
 
   class TransferError < StandardError; end
 
-  attr_accessible :name, :path, :description, :default_branch,
-    :issues_enabled, :wall_enabled, :merge_requests_enabled,
+  attr_accessible :name, :path, :description, :default_branch, :issues_tracker,
+    :issues_enabled, :wall_enabled, :merge_requests_enabled, :issues_tracker_id,
     :wiki_enabled, :public, :import_url, as: [:default, :admin]
 
   attr_accessible :namespace_id, :creator_id, as: :admin
@@ -72,6 +74,7 @@ class Project < ActiveRecord::Base
                       message: "only letters, digits & '_' '-' '.' allowed. Letter should be first" }
   validates :issues_enabled, :wall_enabled, :merge_requests_enabled,
             :wiki_enabled, inclusion: { in: [true, false] }
+  validates :issues_tracker_id, length: { within: 0..255 }
 
   validates_uniqueness_of :name, scope: :namespace_id
   validates_uniqueness_of :path, scope: :namespace_id
@@ -93,6 +96,8 @@ class Project < ActiveRecord::Base
   scope :joined, ->(user) { where("namespace_id != ?", user.namespace_id) }
   scope :public_only, -> { where(public: true) }
 
+  enumerize :issues_tracker, :in => (Gitlab.config.issues_tracker.keys).append(:gitlab), :default => :gitlab
+
   class << self
     def abandoned
       project_ids = Event.select('max(created_at) as latest_date, project_id').
@@ -201,6 +206,22 @@ class Project < ActiveRecord::Base
     issues.tag_counts_on(:labels)
   end
 
+  def issue_exists?(issue_id)
+    if used_default_issues_tracker?
+      self.issues.where(id: issue_id).first.present?
+    else
+      true
+    end
+  end
+
+  def used_default_issues_tracker?
+    self.issues_tracker == Project.issues_tracker.default_value
+  end
+
+  def can_have_issues_tracker_id?
+    self.issues_enabled && !self.used_default_issues_tracker?
+  end
+
   def services
     [gitlab_ci_service].compact
   end
diff --git a/app/views/admin/projects/_form.html.haml b/app/views/admin/projects/_form.html.haml
index ebf69924a25..29b90bdd4cb 100644
--- a/app/views/admin/projects/_form.html.haml
+++ b/app/views/admin/projects/_form.html.haml
@@ -31,6 +31,15 @@
       = f.label :issues_enabled, "Issues"
       .input= f.check_box :issues_enabled
 
+    - if Project.issues_tracker.values.count > 1
+      .clearfix
+        = f.label :issues_tracker, "Issues tracker", class: 'control-label'
+        .input= f.select(:issues_tracker, Project.issues_tracker.values, {}, { disabled: !@project.issues_enabled })
+
+      .clearfix
+        = f.label :issues_tracker_id, "Project name or id in issues tracker", class: 'control-label'
+        .input= f.text_field :issues_tracker_id, class: "xxlarge", disabled: !@project.can_have_issues_tracker_id?
+
     .clearfix
       = f.label :merge_requests_enabled, "Merge Requests"
       .input= f.check_box :merge_requests_enabled
diff --git a/app/views/layouts/_head.html.haml b/app/views/layouts/_head.html.haml
index 4b4f5da3324..eb83fd2fd45 100644
--- a/app/views/layouts/_head.html.haml
+++ b/app/views/layouts/_head.html.haml
@@ -7,6 +7,7 @@
   = stylesheet_link_tag    "application"
   = javascript_include_tag "application"
   = csrf_meta_tags
+  = include_gon
 
   -# Atom feed
   - if current_user
diff --git a/app/views/layouts/project_resource.html.haml b/app/views/layouts/project_resource.html.haml
index 3b689215870..37d0f16fa20 100644
--- a/app/views/layouts/project_resource.html.haml
+++ b/app/views/layouts/project_resource.html.haml
@@ -22,11 +22,12 @@
             = nav_link(controller: %w(graph)) do
               = link_to "Network", project_graph_path(@project, @ref || @repository.root_ref)
 
-        - if @project.issues_enabled
+        - if @project.issues_enabled 
           = nav_link(controller: %w(issues milestones labels)) do
-            = link_to  project_issues_filter_path(@project)  do
+            = link_to url_for_project_issues do
               Issues
-              %span.count.issue_counter= @project.issues.opened.count
+              - if @project.used_default_issues_tracker?
+                %span.count.issue_counter= @project.issues.opened.count
 
         - if @project.repo_exists? && @project.merge_requests_enabled
           = nav_link(controller: :merge_requests) do
diff --git a/app/views/projects/_form.html.haml b/app/views/projects/_form.html.haml
index 0336654dc69..b78c70be18a 100644
--- a/app/views/projects/_form.html.haml
+++ b/app/views/projects/_form.html.haml
@@ -24,6 +24,15 @@
         = f.check_box :issues_enabled
         %span.descr Lightweight issue tracking system for this project
 
+    - if Project.issues_tracker.values.count > 1
+      .control-group
+        = f.label :issues_tracker, "Issues tracker", class: 'control-label'
+        .input= f.select(:issues_tracker, Project.issues_tracker.values, {}, { disabled: !@project.issues_enabled })
+
+      .clearfix
+        = f.label :issues_tracker_id, "Project name or id in issues tracker", class: 'control-label'
+        .input= f.text_field :issues_tracker_id, class: "xxlarge", disabled: !@project.can_have_issues_tracker_id?
+
     .control-group
       = f.label :merge_requests_enabled, "Merge Requests", class: 'control-label'
       .controls
diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index 62761c80cbb..07e97ae5414 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -37,6 +37,22 @@ production: &base
     # signup_enabled: true          # default: false - Account passwords are not sent via the email if signup is enabled.
     # username_changing_enabled: false # default: true - User can change her username/namespace
 
+
+  ## External issues trackers
+  issues_tracker:
+    redmine:
+      ## If not nil, link 'Issues' on project page will be replaced tp this
+      ## Use placeholders:
+      ##  :project_id        - Gitlab project identifier
+      ##  :issues_tracker_id - Project Name or Id in external issue tracker
+      project_url: "http://redmine.sample/projects/:issues_tracker_id"
+      ## If not nil, links from /#\d/ entities from commit messages will replaced to this
+      ## Use placeholders:
+      ##  :project_id        - Gitlab project identifier
+      ##  :issues_tracker_id - Project Name or Id in external issue tracker
+      ##  :id                - Issue id (from commit messages)
+      issues_url: "http://redmine.sample/issues/:id"
+
   ## Gravatar
   gravatar:
     enabled: true                 # Use user avatar images from Gravatar.com (default: true)
@@ -133,6 +149,10 @@ development:
 
 test:
   <<: *base
+  issues_tracker:
+    redmine:
+      project_url: "http://redmine/projects/:issues_tracker_id"
+      issues_url: "http://redmine/:project_id/:issues_tracker_id/:id"
 
 staging:
   <<: *base
diff --git a/config/initializers/1_settings.rb b/config/initializers/1_settings.rb
index f7d18e67148..a656b02171f 100644
--- a/config/initializers/1_settings.rb
+++ b/config/initializers/1_settings.rb
@@ -42,6 +42,8 @@ Settings['omniauth'] ||= Settingslogic.new({})
 Settings.omniauth['enabled']      = false if Settings.omniauth['enabled'].nil?
 Settings.omniauth['providers']  ||= []
 
+Settings['issues_tracker']  ||= {}
+
 #
 # GitLab
 #
diff --git a/db/migrate/20130123114545_add_issues_tracker_to_project.rb b/db/migrate/20130123114545_add_issues_tracker_to_project.rb
new file mode 100644
index 00000000000..288d0f07c9a
--- /dev/null
+++ b/db/migrate/20130123114545_add_issues_tracker_to_project.rb
@@ -0,0 +1,5 @@
+class AddIssuesTrackerToProject < ActiveRecord::Migration
+  def change
+    add_column :projects, :issues_tracker, :string, default: :gitlab, null: false
+  end
+end
diff --git a/db/migrate/20130211085435_add_issues_tracker_id_to_project.rb b/db/migrate/20130211085435_add_issues_tracker_id_to_project.rb
new file mode 100644
index 00000000000..71763d18aee
--- /dev/null
+++ b/db/migrate/20130211085435_add_issues_tracker_id_to_project.rb
@@ -0,0 +1,5 @@
+class AddIssuesTrackerIdToProject < ActiveRecord::Migration
+  def change
+    add_column :projects, :issues_tracker_id, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 74d5f9a360c..e9d428e5ef5 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -106,11 +106,11 @@ ActiveRecord::Schema.define(:version => 20130220133245) do
   add_index "milestones", ["project_id"], :name => "index_milestones_on_project_id"
 
   create_table "namespaces", :force => true do |t|
-    t.string   "name",                        :null => false
-    t.string   "path",                        :null => false
-    t.integer  "owner_id",                    :null => false
-    t.datetime "created_at",                  :null => false
-    t.datetime "updated_at",                  :null => false
+    t.string   "name",       :null => false
+    t.string   "path",       :null => false
+    t.integer  "owner_id",   :null => false
+    t.datetime "created_at", :null => false
+    t.datetime "updated_at", :null => false
     t.string   "type"
   end
 
@@ -152,6 +152,8 @@ ActiveRecord::Schema.define(:version => 20130220133245) do
     t.boolean  "wiki_enabled",           :default => true,     :null => false
     t.integer  "namespace_id"
     t.boolean  "public",                 :default => false,    :null => false
+    t.string   "issues_tracker",         :default => "gitlab", :null => false
+    t.string   "issues_tracker_id"
   end
 
   add_index "projects", ["creator_id"], :name => "index_projects_on_owner_id"
@@ -230,8 +232,8 @@ ActiveRecord::Schema.define(:version => 20130220133245) do
     t.string   "name"
     t.string   "path"
     t.integer  "owner_id"
-    t.datetime "created_at",                  :null => false
-    t.datetime "updated_at",                  :null => false
+    t.datetime "created_at", :null => false
+    t.datetime "updated_at", :null => false
   end
 
   create_table "users", :force => true do |t|
diff --git a/lib/gitlab/markdown.rb b/lib/gitlab/markdown.rb
index e7d6e3e6bd9..280f9f9730a 100644
--- a/lib/gitlab/markdown.rb
+++ b/lib/gitlab/markdown.rb
@@ -25,6 +25,8 @@ module Gitlab
   #   >> gfm(":trollface:")
   #   => "<img alt=\":trollface:\" class=\"emoji\" src=\"/images/trollface.png" title=\":trollface:\" />
   module Markdown
+    include IssuesHelper
+
     attr_reader :html_options
 
     # Public: Parse the provided text with GitLab-Flavored Markdown
@@ -163,8 +165,11 @@ module Gitlab
     end
 
     def reference_issue(identifier)
-      if issue = @project.issues.where(id: identifier).first
-        link_to("##{identifier}", project_issue_url(@project, issue), html_options.merge(title: "Issue: #{issue.title}", class: "gfm gfm-issue #{html_options[:class]}"))
+      if @project.issue_exists? identifier
+        url = url_for_issue(identifier)
+        title = title_for_issue(identifier)
+
+        link_to("##{identifier}", url, html_options.merge(title: "Issue: #{title}", class: "gfm gfm-issue #{html_options[:class]}"))
       end
     end
 
diff --git a/spec/factories.rb b/spec/factories.rb
index b81984b5d53..41766859468 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -29,6 +29,11 @@ FactoryGirl.define do
     creator
   end
 
+  factory :redmine_project, parent: :project do
+    issues_tracker { "redmine" }
+    issues_tracker_id { "project_name_in_redmine" }
+  end
+
   factory :group do
     sequence(:name) { |n| "group#{n}" }
     path { name.downcase.gsub(/\s/, '_') }
diff --git a/spec/helpers/gitlab_markdown_helper_spec.rb b/spec/helpers/gitlab_markdown_helper_spec.rb
index 1b067972c81..1f5fabfbb8e 100644
--- a/spec/helpers/gitlab_markdown_helper_spec.rb
+++ b/spec/helpers/gitlab_markdown_helper_spec.rb
@@ -2,6 +2,7 @@ require "spec_helper"
 
 describe GitlabMarkdownHelper do
   include ApplicationHelper
+  include IssuesHelper
 
   let!(:project) { create(:project) }
 
diff --git a/spec/helpers/issues_helper_spec.rb b/spec/helpers/issues_helper_spec.rb
new file mode 100644
index 00000000000..c9eb6591561
--- /dev/null
+++ b/spec/helpers/issues_helper_spec.rb
@@ -0,0 +1,79 @@
+require "spec_helper"
+
+describe IssuesHelper do
+  let(:project) { create :project }
+  let(:issue) { create :issue, project: project }
+  let(:ext_project) { create :redmine_project }
+
+  describe :title_for_issue do
+    it "should return issue title if used internal tracker" do
+      @project = project
+      title_for_issue(issue.id).should eq issue.title
+    end
+
+    it "should always return empty string if used external tracker" do
+      @project = ext_project
+      title_for_issue(rand(100)).should eq ""
+    end
+
+    it "should always return empty string if project nil" do
+      @project = nil
+
+      title_for_issue(rand(100)).should eq ""
+    end
+  end
+
+  describe :url_for_project_issues do
+    let(:project_url) { Gitlab.config.issues_tracker.redmine.project_url}
+    let(:ext_expected) do
+      project_url.gsub(':project_id', ext_project.id.to_s)
+                 .gsub(':issues_tracker_id', ext_project.issues_tracker_id.to_s)
+    end
+    let(:int_expected) { polymorphic_path([project]) }
+
+    it "should return internal path if used internal tracker" do
+      @project = project
+      url_for_project_issues.should match(int_expected)
+    end
+
+    it "should return path to external tracker" do
+      @project = ext_project
+
+      url_for_project_issues.should match(ext_expected)
+    end
+
+    it "should return empty string if project nil" do
+      @project = nil
+
+      url_for_project_issues.should eq ""
+    end
+  end
+
+  describe :url_for_issue do
+    let(:issue_id) { 3 }
+    let(:issues_url) { Gitlab.config.issues_tracker.redmine.issues_url}
+    let(:ext_expected) do
+      issues_url.gsub(':id', issue_id.to_s)
+        .gsub(':project_id', ext_project.id.to_s)
+        .gsub(':issues_tracker_id', ext_project.issues_tracker_id.to_s)
+    end
+    let(:int_expected) { polymorphic_path([project, issue]) }
+
+    it "should return internal path if used internal tracker" do
+      @project = project
+      url_for_issue(issue.id).should match(int_expected)
+    end
+
+    it "should return path to external tracker" do
+      @project = ext_project
+
+      url_for_issue(issue_id).should match(ext_expected)
+    end
+
+    it "should return empty string if project nil" do
+      @project = nil
+
+      url_for_issue(issue.id).should eq ""
+    end
+  end
+end
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index 48432eac147..44f4cd4a737 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -60,6 +60,7 @@ describe Project do
     it { should ensure_inclusion_of(:wall_enabled).in_array([true, false]) }
     it { should ensure_inclusion_of(:merge_requests_enabled).in_array([true, false]) }
     it { should ensure_inclusion_of(:wiki_enabled).in_array([true, false]) }
+    it { should ensure_length_of(:issues_tracker_id).is_within(0..255) }
 
     it "should not allow new projects beyond user limits" do
       project.stub(:creator).and_return(double(can_create_project?: false, projects_limit: 1))
@@ -190,4 +191,57 @@ describe Project do
       Project.new(path: "empty").repository.should be_nil
     end
   end
+
+  describe :issue_exists? do
+    let(:project) { create(:project) }
+    let(:existed_issue) { create(:issue, project: project) }
+    let(:not_existed_issue) { create(:issue) }
+    let(:ext_project) { create(:redmine_project) }
+
+    it "should be true or if used internal tracker and issue exists" do
+      project.issue_exists?(existed_issue.id).should be_true
+    end
+
+    it "should be false or if used internal tracker and issue not exists" do
+      project.issue_exists?(not_existed_issue.id).should be_false
+    end
+
+    it "should always be true if used other tracker" do
+      ext_project.issue_exists?(rand(100)).should be_true
+    end
+  end
+
+  describe :used_default_issues_tracker? do
+    let(:project) { create(:project) }
+    let(:ext_project) { create(:redmine_project) }
+
+    it "should be true if used internal tracker" do
+      project.used_default_issues_tracker?.should be_true
+    end
+
+    it "should be false if used other tracker" do
+      ext_project.used_default_issues_tracker?.should be_false
+    end
+  end
+
+  describe :can_have_issues_tracker_id? do
+    let(:project) { create(:project) }
+    let(:ext_project) { create(:redmine_project) }
+
+    it "should be true for projects with external issues tracker if issues enabled" do
+      ext_project.can_have_issues_tracker_id?.should be_true
+    end 
+
+    it "should be false for projects with internal issue tracker if issues enabled" do
+      project.can_have_issues_tracker_id?.should be_false
+    end
+
+    it "should be always false if issues disbled" do
+      project.issues_enabled = false
+      ext_project.issues_enabled = false
+
+      project.can_have_issues_tracker_id?.should be_false
+      ext_project.can_have_issues_tracker_id?.should be_false
+    end
+  end
 end