The revenge epic was also awarded the Best Fight prize, for the clash between Thurman's character and schoolgirl CHYIAKI KURIYAMA.
A grateful Thurman praised Tarantino as she collected the award: "Quentin spent many years writing this for me and wants to be honoured as if he were dead tonight.
"We don't have time, so I'll have to honour you as if you were living. Thank you, Quentin."
The Return Of The King, the third film in director Peter Jackson's blockbusting Lord Of The Rings trilogy, won Best Movie and Best Action Sequence.
Best Kiss went to the smooch shared between Owen Wilson, Amy Smart and Carmen Electra in STARSKY + HUTCH, while Adam Sandler and Drew Barrymore were named the Best Onscreen Team for their partnership in 50 FIRST DATES.