The Harry Potter star has a leading role in The Bling Ring, about the real-life teens who stole from the homes of A-listers including Paris Hilton, Lindsay Lohan and Orlando Bloom.
Watson was less than impressed with her wardrobe, which included Ugg boots, a tight pink tracksuit and fake tattoos, and won't be watching the drama when it hits theatres.
She tells MTV News, "This is how much I hate myself in the movie: I don't think I'm going to be able to watch it. It's the first time I couldn't watch myself...
"I also want to point out on my lower back, I have an Om Buddha sign, like a tramp stamp. It was really weird.
"This is what's so awesome about my job, is that I had to get into the shoes of someone I couldn't relate to. I've never had to do that before, but by the end of it, I don't know, it was really interesting getting into this girl's head. She represents a lot of what I basically stand against. It was really fascinating to break it down, and be like, 'What is this actually about?' It made me like my job a lot."