Can an iMac (Aug 2011) be used in target display mode with my MacBook Air (2012)?

I want to use an Aug 2011 iMac (21.5 inch) as a second display with a new Mac Book Air.
Is this possible with a Thunderbolt cable?

Apple Thunderbolt Cable

Apple Thunderbolt Cable

Product No Longer Available

3 Answers from the Community

  • Best Answer:

    You can use any iMac with a Thunderbolt port as an external monitor for another Mac that has a Thunderbolt port as well. If you have the education-only model of the 21.5" iMac that started selling in august of 2011, you're out of luck, because it has not Thunderbolt port.

  • No only the 27 inch can be a display. Not the 21.5.

  • Yes you can. I am using mine right now. Just make sure you have the latest OSX update installed.