The actress plays teenager Jill Roberts in the latest instalment of the slasher franchise, which promises as many shocks as the previous films.
"The secrecy part is really hard because you so want to run out and tell your friends every amazing part about it," she revealed.
Emma's co-star David Arquette, who reprises his role as Sheriff Dewey in the Wes Craven film, said he couldn't comprehend why people who'd seen the film would want to give away the ending."I hate people that spoil things for me when I'm going to see a film," he said.
"It's kind of a creepy personality trait: wanting to be the person that ruins things."
The filmmakers have worked hard to keep Scream 4 under wraps. Director Wes revealed the movie has only been shown six times ahead of media previews.
"We took everyone's cell phones, we made them sign non-disclosure agreements, and we went on the internet and watched all night to see who posted what... by and large, people honoured our plea to keep it a secret," he said.
The film, due for release in the UK later this month, also stars Courteney Cox, who separated from her husband and co-star David last year
