diff --git a/lib/aasm.rb b/lib/aasm.rb
index bbf868d..bcc57e3 100644
--- a/lib/aasm.rb
+++ b/lib/aasm.rb
@@ -49,12 +49,12 @@ module AASM
         sm.events[name] = AASM::SupportingClasses::Event.new(name, options, &block)
       end
 
-      define_method("#{name.to_s}!") do
-        aasm_fire_event(name, true)
+      define_method("#{name.to_s}!") do |*args|
+        aasm_fire_event(name, true, *args)
       end
 
-      define_method("#{name.to_s}") do
-        aasm_fire_event(name, false)
+      define_method("#{name.to_s}") do |*args|
+        aasm_fire_event(name, false, *args)
       end
     end
 
@@ -111,10 +111,10 @@ module AASM
     self.class.aasm_states.find {|s| s == name}
   end
 
-  def aasm_fire_event(name, persist)
+  def aasm_fire_event(name, persist, *args)
     aasm_state_object_for_state(aasm_current_state).call_action(:exit, self)
 
-    new_state = self.class.aasm_events[name].fire(self)
+    new_state = self.class.aasm_events[name].fire(self, *args)
     
     unless new_state.nil?
       aasm_state_object_for_state(new_state).call_action(:enter, self)
diff --git a/lib/event.rb b/lib/event.rb
index 6ec86b5..2e943ef 100644
--- a/lib/event.rb
+++ b/lib/event.rb
@@ -12,14 +12,16 @@ module AASM
         instance_eval(&block) if block
       end
 
-      def fire(obj)
+      def fire(obj, to_state=nil, *args)
         transitions = @transitions.select { |t| t.from == obj.aasm_current_state }
         raise AASM::InvalidTransition if transitions.size == 0
 
         next_state = nil
         transitions.each do |transition|
+          next if to_state and !Array(transition.to).include?(to_state)
           if transition.perform(obj)
-            next_state = transition.to
+            next_state = to_state || Array(transition.to).first
+            transition.execute(obj, *args)
             break
           end
         end
diff --git a/lib/state_transition.rb b/lib/state_transition.rb
index 5955f34..f82f5d4 100644
--- a/lib/state_transition.rb
+++ b/lib/state_transition.rb
@@ -4,7 +4,7 @@ module AASM
       attr_reader :from, :to, :opts
 
       def initialize(opts)
-        @from, @to, @guard = opts[:from], opts[:to], opts[:guard]
+        @from, @to, @guard, @on_transition = opts[:from], opts[:to], opts[:guard], opts[:on_transition]
         @opts = opts
       end
 
@@ -19,6 +19,15 @@ module AASM
         end
       end
       
+      def execute(obj, *args)
+        case @on_transition
+        when Symbol, String
+          obj.send(@on_transition, *args)
+        when Proc
+          @on_transition.call(obj, *args)
+        end
+      end
+
       def ==(obj)
         @from == obj.from && @to == obj.to
       end
diff --git a/spec/unit/aasm_spec.rb b/spec/unit/aasm_spec.rb
index 7d7bf90..33e9d9b 100644
--- a/spec/unit/aasm_spec.rb
+++ b/spec/unit/aasm_spec.rb
@@ -270,3 +270,72 @@ describe Baz do
     Baz.aasm_events.should == Bar.aasm_events
   end
 end
+
+
+class ChetanPatil
+  include AASM
+  aasm_initial_state :sleeping
+  aasm_state :sleeping
+  aasm_state :showering
+  aasm_state :working
+  aasm_state :dating
+
+  aasm_event :wakeup do
+    transitions :from => :sleeping, :to => [:showering, :working]
+  end
+
+  aasm_event :dress do
+    transitions :from => :sleeping, :to => :working, :on_transition => :wear_clothes
+    transitions :from => :showering, :to => [:working, :dating], :on_transition => Proc.new { |obj, *args| obj.wear_clothes(*args) }
+  end
+
+  def wear_clothes(shirt_color, trouser_type)
+  end
+end
+
+
+describe ChetanPatil do
+  it 'should transition to specified next state (sleeping to showering)' do
+    cp = ChetanPatil.new
+    cp.wakeup! :showering
+    
+    cp.aasm_current_state.should == :showering
+  end
+
+  it 'should transition to specified next state (sleeping to working)' do
+    cp = ChetanPatil.new
+    cp.wakeup! :working
+
+    cp.aasm_current_state.should == :working
+  end
+
+  it 'should transition to default (first or showering) state' do
+    cp = ChetanPatil.new
+    cp.wakeup!
+
+    cp.aasm_current_state.should == :showering
+  end
+
+  it 'should transition to default state when on_transition invoked' do
+    cp = ChetanPatil.new
+    cp.dress!(nil, 'purple', 'dressy')
+
+    cp.aasm_current_state.should == :working
+  end
+
+  it 'should call on_transition method with args' do
+    cp = ChetanPatil.new
+    cp.wakeup! :showering
+
+    cp.should_receive(:wear_clothes).with('blue', 'jeans')
+    cp.dress! :working, 'blue', 'jeans'
+  end
+
+  it 'should call on_transition proc' do
+    cp = ChetanPatil.new
+    cp.wakeup! :showering
+
+    cp.should_receive(:wear_clothes).with('purple', 'slacks')
+    cp.dress!(:dating, 'purple', 'slacks')
+  end
+end