diff --git a/package.json b/package.json
index b15b198a4..cabeae2da 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
     "tantamount": "0.3.0",
     "nslog": "0.1.0",
     "coffeestack": "0.4.0",
+    "first-mate": "0.1.0",
     "c-tmbundle": "1.0.0",
     "coffee-script-tmbundle": "4.0.0",
     "css-tmbundle": "1.0.0",
diff --git a/tasks/convert-theme.coffee b/tasks/convert-theme.coffee
new file mode 100644
index 000000000..2d9884ed0
--- /dev/null
+++ b/tasks/convert-theme.coffee
@@ -0,0 +1,101 @@
+path = require 'path'
+
+_ = require 'underscore'
+plist = require 'plist'
+{ScopeSelector} = require 'first-mate'
+
+module.exports = (grunt) ->
+  grunt.registerTask 'convert-theme', 'Convert a TextMate theme to an Atom theme', ->
+    if textMateThemePath = grunt.option('path')
+      textMateThemePath = path.resolve(textMateThemePath)
+      if grunt.file.isFile(textMateThemePath)
+        textMateTheme = new TextMateTheme(textMateThemePath)
+        atomThemePath = path.join(path.dirname(textMateThemePath), "#{path.basename(textMateThemePath, path.extname(textMateThemePath))}.css")
+        grunt.file.write(atomThemePath, textMateTheme.getStylesheet())
+        grunt.log.ok("Atom theme written to: #{atomThemePath}")
+      else
+        grunt.log.error("Theme file at path not found: #{textMateThemePath}")
+        false
+    else
+      grunt.log.error('Must specify --path=<path to TextMate theme>')
+      false
+
+class TextMateTheme
+  constructor: (@path) ->
+    @rulesets = []
+    @buildRulesets()
+
+  buildRulesets: ->
+    {settings} = plist.parseFileSync(@path)
+    @buildGlobalSettingsRulesets(settings[0])
+    @buildScopeSelectorRulesets(settings[1..])
+
+  getStylesheet: ->
+    lines = []
+    for {selector, properties} in @getRulesets()
+      lines.push("#{selector} {")
+      lines.push "  #{name}: #{value};" for name, value of properties
+      lines.push("}\n")
+    lines.join('\n')
+
+  getRulesets: -> @rulesets
+
+  buildGlobalSettingsRulesets: ({settings}) ->
+    { background, foreground, caret, selection, lineHighlight } = settings
+
+    @rulesets.push
+      selector: '.editor, .editor .gutter'
+      properties:
+        'background-color': @translateColor(background)
+        'color': @translateColor(foreground)
+
+    @rulesets.push
+      selector: '.editor.is-focused .cursor'
+      properties:
+        'border-color': @translateColor(caret)
+
+    @rulesets.push
+      selector: '.editor.is-focused .selection .region'
+      properties:
+        'background-color': @translateColor(selection)
+
+    @rulesets.push
+      selector: '.editor.is-focused .line-number.cursor-line-no-selection, .editor.is-focused .line.cursor-line'
+      properties:
+        'background-color': @translateColor(lineHighlight)
+
+  buildScopeSelectorRulesets: (scopeSelectorSettings) ->
+    for { name, scope, settings } in scopeSelectorSettings
+      continue unless scope
+      @rulesets.push
+        comment: name
+        selector: @translateScopeSelector(scope)
+        properties: @translateScopeSelectorSettings(settings)
+
+  translateScopeSelector: (textmateScopeSelector) ->
+    new ScopeSelector(textmateScopeSelector).toCssSelector()
+
+  translateScopeSelectorSettings: ({ foreground, background, fontStyle }) ->
+    properties = {}
+
+    if fontStyle
+      fontStyles = fontStyle.split(/\s+/)
+      properties['font-weight'] = 'bold' if _.contains(fontStyles, 'bold')
+      properties['font-style'] = 'italic' if _.contains(fontStyles, 'italic')
+      properties['text-decoration'] = 'underline' if _.contains(fontStyles, 'underline')
+
+    properties['color'] = @translateColor(foreground) if foreground
+    properties['background-color'] = @translateColor(background) if background
+    properties
+
+  translateColor: (textmateColor) ->
+    if textmateColor.length <= 7
+      textmateColor
+    else
+      r = parseInt(textmateColor[1..2], 16)
+      g = parseInt(textmateColor[3..4], 16)
+      b = parseInt(textmateColor[5..6], 16)
+      a = parseInt(textmateColor[7..8], 16)
+      a = Math.round((a / 255.0) * 100) / 100
+
+      "rgba(#{r}, #{g}, #{b}, #{a})"