diff --git a/BUILD.md b/BUILD.md
index e5dd2b42..2b949340 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -51,7 +51,7 @@ Each time you start work:
 . env/bin/activate
 ```
 
-Build the .app:
+To build the .app:
 
 ```sh
 pyinstaller -w -y setup/onionshare-osx.spec
@@ -59,6 +59,12 @@ pyinstaller -w -y setup/onionshare-osx.spec
 
 Now you should have `dist/OnionShare.app`.
 
+To build a .dmg (this script builds the .app for you):
+
+```sh
+setup/build_dmg.sh
+```
+
 ## Windows
 
 The first time you're setting up your dev environment:
diff --git a/build_dmg.sh b/build_dmg.sh
new file mode 100755
index 00000000..9b451bb5
--- /dev/null
+++ b/build_dmg.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+
+ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+DMG_DIR=$ROOT/dist/dmg
+DMG_TMP_NAME=$ROOT/dist/tmp.dmg
+DMG_NAME=$ROOT/dist/OnionShare.dmg
+TITLE=OnionShare
+VOLUME=/Volumes/$TITLE
+
+cd $ROOT
+
+# deleting dist
+echo Deleting dist folder
+rm -rf $ROOT/dist &>/dev/null 2>&1
+
+# build the .app
+echo Building OnionShare.app 
+pyinstaller -w -y $ROOT/setup/onionshare-osx.spec
+
+# create the .dmg
+echo Creating DMG
+mkdir -p $DMG_DIR
+hdiutil create -srcfolder $DMG_DIR -volname $TITLE -fs HFS+ -fsargs "-c c=64,a=16,e=16" -format UDRW -size 100mb $DMG_TMP_NAME
+DEVICE=$(hdiutil attach -readwrite -noverify -noautoopen $DMG_TMP_NAME | egrep '^/dev/' | sed 1q | awk '{print $1}')
+sleep 10
+
+# set up the dmg
+echo Setting up DMG
+cp -r $ROOT/dist/OnionShare.app $VOLUME
+ln -s /Applications $VOLUME/Applications
+mkdir $VOLUME/.background
+cp $ROOT/setup/dmg_background.png $VOLUME/.background/background.png
+echo '
+   tell application "Finder"
+     tell disk "'${TITLE}'"
+           open
+           set current view of container window to icon view
+           set toolbar visible of container window to false
+           set statusbar visible of container window to false
+           set the bounds of container window to {100, 100, 400, 480}
+           set theViewOptions to the icon view options of container window
+           set arrangement of theViewOptions to not arranged
+           set icon size of theViewOptions to 72
+           set background picture of theViewOptions to file ".background:background.png"
+           set position of item "'${TITLE}.app'" of container window to {60, 288}
+           set position of item "Applications" of container window to {268, 288}
+           update without registering applications
+           delay 10
+           eject
+     end tell
+   end tell
+' | osascript
+
+# finalize the DMG
+echo Finalizing DMG
+hdiutil convert $DMG_TMP_NAME -format UDZO -imagekey zlib-level=9 -o $DMG_NAME
+rm -r $DMG_DIR
+rm -f $DMG_TMP_NAME
+
+# all done
+echo DMG created: $DMG_NAME
diff --git a/setup/dmg_background.png b/setup/dmg_background.png
new file mode 100644
index 00000000..c3a02fcb
Binary files /dev/null and b/setup/dmg_background.png differ