I also have horrible, vivid nightmares on prozac, and others. Since these meds make me unable to fall asleep I also take a sleeping pill. The sleep med seems to help with the vivid dreams. I still have some nightmares, I think everyone does, especially when I am working on some tough stuff in therapy, but they aren't as frequent and as vivid now. I'm certainly not advocating adding a sleep med, just letting you know that prozac can definitely do that. Take care and HUGS!