For the most part, no... you cant get all the work back.
If you were testing your flash along the way, you will have a swf file of the most recent test, and you can sometimes grab some ghetto information from that.
If you were making a game, you may be able to recover some of your code with a decompiler.
You can probably also recover some of your graphics by importing the swf into flash.
Long story short, there isn't much you can do, but you might be able to recover some of it.