Angelina Jolie, Halle Berry, Nicole Kidman and More: 15 Celebrities Who Did Full Frontal Nudity (GALLERY)
The Brit, 22, told Hello magazine she has been thinking of baring all since she was a teenager.
"I've thought since I was 16 that if it's important for the character to do sex scenes then I would," she said. "If it's important to the story then I'll do it, because I'm an actress."
View of gallery of 15 stars who did full frontal in films, then click after the jump to find out if Watson is attached to 50 Shades of Grey?
"I'm not attached to that film," she said during a press conference in London, responding to reports that she will play Anastasia Steele in the movie adaptation.
"I don't know why it keeps coming up again and again.
"I've got no idea where this rumor has come from. I just can't seem to shake it. I haven't read the book, I haven't read a script, I haven't been approached."
Watson is currently starring in the coming-of-age drama Perks of Being a Wallflower.