twerppoet said:What version of iOS are you using?
The ability to edit in the Photos app was introduced in iOS 5. If the video is in the Camera Roll album, it should be editable in the Photos app. If it has been synced back from the computer using iTunes (in a synced album), it can not be edited in the Photos app.
You can edit video synced to a Photos album in iMovie, and probably some other third party video editing apps.