The sci-fi epic won the coveted Best Film honour and Cameron landed the Best Director award, while Zoe Saldana was named the Best Actress at the ceremony in London.
Inglourious Basterds star Christoph Waltz won the Best Actor award for his role in Quentin Tarantino's movie, while Aaron Johnson won the Best Newcomer honour for his portrayal of a young John Lennon in Nowhere Boy.
Guy Ritchie's Sherlock Holmes landed the Best Thriller film award and Star Trek won Best Sci-Fi/Fantasy film.
British actor Ray Winstone, Jude Law, Andy Serkis and Sir Ian McKellen all won special awards for their contribution to film, with the X-Men star being named Empire Icon, the evening's top honour.
He says, "I've played iconic parts - I think that's the point. I played Gandalf the Grey and the White and Magneto. So their lustre rubs off on me rather than the other way round."
The list of winners is as follows:
Best Film: Avatar
Best Director: James Cameron (Avatar)
Best Actor: Christoph Waltz (Inglourious Basterds)
Best Actress: Zoe Saldana (Avatar)
Best Newcomer: Aaron Johnson (Nowhere Boy)
Best Thriller: Sherlock Holmes
Best Sci-Fi/Fantasy Film: Star Trek
Best Horror: Let The Right One In
Best Comedy: In The Loop
Best British Film: Harry Brown
Outstanding Contribution To British Film: Ray Winstone
Empire Hero: Jude Law
Inspiration award: Andy Serkis
Empire Icon: Sir Ian McKellen.