diff --git a/CHANGELOG b/CHANGELOG
index 58a0a3c8944..f21129c6d61 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -9,6 +9,7 @@ v 8.3.0 (unreleased)
   - Don't show project fork event as "imported"
   - Add API endpoint to fetch merge request commits list
   - Expose events API with comment information and author info
+  - Fix: Ensure "Remove Source Branch" button is not shown when branch is being deleted. #3583
 
 v 8.2.2
   - Fix 404 in redirection after removing a project (Stan Hu)
diff --git a/app/assets/javascripts/merge_request_widget.js.coffee b/app/assets/javascripts/merge_request_widget.js.coffee
index 3176e5a8965..c4b63966fe7 100644
--- a/app/assets/javascripts/merge_request_widget.js.coffee
+++ b/app/assets/javascripts/merge_request_widget.js.coffee
@@ -10,17 +10,20 @@ class @MergeRequestWidget
   constructor: (@opts) ->
     modal = $('#modal_merge_info').modal(show: false)
 
-  mergeInProgress: ->
+  mergeInProgress: (deleteSourceBranch = false)->
     $.ajax
       type: 'GET'
       url: $('.merge-request').data('url')
       success: (data) =>
         if data.state == "merged"
-          location.reload()
+          urlSuffix = if deleteSourceBranch then '?delete_source=true' else ''
+
+          window.location.href = window.location.href + urlSuffix
         else if data.merge_error
           $('.mr-widget-body').html("<h4>" + data.merge_error + "</h4>")
         else
-          setTimeout(merge_request_widget.mergeInProgress, 2000)
+          callback = -> merge_request_widget.mergeInProgress(deleteSourceBranch)
+          setTimeout(callback, 2000)
       dataType: 'json'
 
   getMergeStatus: ->
diff --git a/app/helpers/gitlab_routing_helper.rb b/app/helpers/gitlab_routing_helper.rb
index b0b536d4649..f3fddef01cb 100644
--- a/app/helpers/gitlab_routing_helper.rb
+++ b/app/helpers/gitlab_routing_helper.rb
@@ -6,7 +6,7 @@
 #
 # For example instead of this:
 #
-#   namespace_project_merge_request_path(merge_request.project.namespace, merge_request.projects, merge_request)
+#   namespace_project_merge_request_path(merge_request.project.namespace, merge_request.project, merge_request)
 #
 # We can simply use shortcut:
 #
diff --git a/app/views/projects/merge_requests/merge.js.haml b/app/views/projects/merge_requests/merge.js.haml
index 33321651e32..518ecb9f00f 100644
--- a/app/views/projects/merge_requests/merge.js.haml
+++ b/app/views/projects/merge_requests/merge.js.haml
@@ -1,6 +1,6 @@
 - if @status
   :plain
-    merge_request_widget.mergeInProgress();
+    merge_request_widget.mergeInProgress(#{params[:should_remove_source_branch] == '1'});
 - else
   :plain
     $('.mr-widget-body').html("#{escape_javascript(render('projects/merge_requests/widget/open/reload'))}");
diff --git a/app/views/projects/merge_requests/widget/_merged.html.haml b/app/views/projects/merge_requests/widget/_merged.html.haml
index ac08e0b498a..5c6fece8c5c 100644
--- a/app/views/projects/merge_requests/widget/_merged.html.haml
+++ b/app/views/projects/merge_requests/widget/_merged.html.haml
@@ -7,7 +7,7 @@
         by #{link_to_member(@project, @merge_request.merge_event.author, avatar: true)}
         #{time_ago_with_tooltip(@merge_request.merge_event.created_at)}
     %div
-      - if !@merge_request.source_branch_exists?
+      - if !@merge_request.source_branch_exists? || (params[:delete_source] == 'true')
         = succeed '.' do
           The changes were merged into
           = link_to namespace_project_commits_path(@project.namespace, @project, @merge_request.target_branch), class: "label-branch" do
diff --git a/features/project/merge_requests/accept.feature b/features/project/merge_requests/accept.feature
new file mode 100644
index 00000000000..3e6e59a3808
--- /dev/null
+++ b/features/project/merge_requests/accept.feature
@@ -0,0 +1,17 @@
+Feature: Project Merge Requests Acceptance
+  Background:
+    Given There is an open Merge Request
+      And I am signed in as a developer of the project
+
+  @javascript
+  Scenario: Accepting the Merge Request and removing the source branch
+    Given I am on the Merge Request detail page
+    When I click on "Remove source branch" option
+    And I click on Accept Merge Request
+    Then I should not see the Remove Source Branch button
+
+  @javascript
+  Scenario: Accepting the Merge Request without removing the source branch
+    Given I am on the Merge Request detail page
+    When I click on Accept Merge Request
+    Then I should see the Remove Source Branch button
diff --git a/features/steps/project/merge_requests/acceptance.rb b/features/steps/project/merge_requests/acceptance.rb
new file mode 100644
index 00000000000..6adecaa8385
--- /dev/null
+++ b/features/steps/project/merge_requests/acceptance.rb
@@ -0,0 +1,35 @@
+class Spinach::Features::ProjectMergeRequestsAcceptance < Spinach::FeatureSteps
+  include LoginHelpers
+  include GitlabRoutingHelper
+
+  step 'I am on the Merge Request detail page' do
+    visit merge_request_path(@merge_request)
+  end
+
+  step 'I click on "Remove source branch" option' do
+    check('Remove source branch')
+  end
+
+  step 'I click on Accept Merge Request' do
+    click_button('Accept Merge Request')
+  end
+
+  step 'I should see the Remove Source Branch button' do
+    expect(page).to have_link('Remove Source Branch')
+  end
+
+  step 'I should not see the Remove Source Branch button' do
+    expect(page).not_to have_link('Remove Source Branch')
+  end
+
+  step 'There is an open Merge Request' do
+    @user = create(:user)
+    @project = create(:project, :public)
+    @project_member = create(:project_member, user: @user, project: @project, access_level: ProjectMember::DEVELOPER)
+    @merge_request = create(:merge_request, :with_diffs, :simple, source_project: @project)
+  end
+
+  step 'I am signed in as a developer of the project' do
+    login_as(@user)
+  end
+end