diff --git a/spec/app/edit-session-spec.coffee b/spec/app/edit-session-spec.coffee
index 047b052b6..cf6ab48a5 100644
--- a/spec/app/edit-session-spec.coffee
+++ b/spec/app/edit-session-spec.coffee
@@ -1871,6 +1871,23 @@ describe "EditSession", ->
         expect(editSession.lineForBufferRow(0)).toBe 'ABc'
         expect(editSession.getSelectedBufferRange()).toEqual [[0, 0], [0, 2]]
 
+  describe ".lowerCase()", ->
+    describe "when there is no selection", ->
+      it "lower cases the current word", ->
+        editSession.buffer.setText("aBC")
+        editSession.setCursorScreenPosition([0, 1])
+        editSession.lowerCase()
+        expect(editSession.lineForBufferRow(0)).toBe 'abc'
+        expect(editSession.getSelectedBufferRange()).toEqual [[0, 1], [0, 1]]
+
+    describe "when there is a selection", ->
+      it "lower cases the current selection", ->
+        editSession.buffer.setText("ABC")
+        editSession.setSelectedBufferRange([[0,0], [0,2]])
+        editSession.lowerCase()
+        expect(editSession.lineForBufferRow(0)).toBe 'abC'
+        expect(editSession.getSelectedBufferRange()).toEqual [[0, 0], [0, 2]]
+
   describe "soft-tabs detection", ->
     it "assign soft / hard tabs based on the contents of the buffer, or uses the default if unknown", ->
       editSession = fixturesProject.buildEditSessionForPath('sample.js', softTabs: false)
diff --git a/src/app/edit-session.coffee b/src/app/edit-session.coffee
index 55bd0fdcd..6b3d8e22b 100644
--- a/src/app/edit-session.coffee
+++ b/src/app/edit-session.coffee
@@ -314,6 +314,17 @@ class EditSession
   mutateSelectedText: (fn) ->
     @transact => fn(selection) for selection in @getSelections()
 
+  replaceSelectedText: (options={}, fn) ->
+    {selectWordIfEmpty} = options
+    @mutateSelectedText (selection) =>
+      range = selection.getBufferRange()
+      if selectWordIfEmpty and selection.isEmpty()
+        selection.selectWord()
+      text = selection.getText()
+      selection.delete()
+      selection.insertText(fn(text))
+      selection.setBufferRange(range)
+
   pushOperation: (operation) ->
     @buffer.pushOperation(operation, this)
 
@@ -553,14 +564,10 @@ class EditSession
         selection.insertText selection.getText().split('').reverse().join('')
 
   upperCase: ->
-    @mutateSelectedText (selection) =>
-      range = selection.getBufferRange()
-      if selection.isEmpty()
-        selection.selectWord()
-      text = selection.getText()
-      selection.delete()
-      selection.insertText text.toUpperCase()
-      selection.setBufferRange(range) if range
+    @replaceSelectedText selectWordIfEmpty:true, (text) => text.toUpperCase()
+
+  lowerCase: ->
+    @replaceSelectedText selectWordIfEmpty:true, (text) => text.toLowerCase()
 
   expandLastSelectionOverLine: ->
     @getLastSelection().expandOverLine()
diff --git a/src/app/editor.coffee b/src/app/editor.coffee
index e25a7cc8b..6bf7db30c 100644
--- a/src/app/editor.coffee
+++ b/src/app/editor.coffee
@@ -134,6 +134,7 @@ class Editor extends View
       'editor:select-to-beginning-of-word': @selectToBeginningOfWord
       'editor:transpose': @transpose
       'editor:upper-case': @upperCase
+      'editor:lower-case': @lowerCase
 
     unless @mini
       _.extend editorBindings,
@@ -228,6 +229,7 @@ class Editor extends View
   selectToScreenPosition: (position) -> @activeEditSession.selectToScreenPosition(position)
   transpose: -> @activeEditSession.transpose()
   upperCase: -> @activeEditSession.upperCase()
+  lowerCase: -> @activeEditSession.lowerCase()
   clearSelections: -> @activeEditSession.clearSelections()
 
   backspace: -> @activeEditSession.backspace()
diff --git a/src/app/keymaps/editor.cson b/src/app/keymaps/editor.cson
index b2106ca59..cb3675501 100644
--- a/src/app/keymaps/editor.cson
+++ b/src/app/keymaps/editor.cson
@@ -32,3 +32,4 @@
   'ctrl-W': 'editor:select-word'
   'meta-alt-p': 'editor:log-cursor-scope'
   'meta-u': 'editor:upper-case'
+  'meta-U': 'editor:lower-case'