The first of the Kill Bill films, marking director Quentin Tarantino's return after six years, premièred in the US on Monday night.
Tarantino with Thurman: Kill Bill is his first film since 1997
Tarantino and star Uma Thurman opened the film in Los Angeles. The movie has been cut in half, with part two being released early next year.
It stars Thurman as an assassin trying to kill her treacherous former boss.
"It's so violent. People will leave the movie theatre or get sick in the movie theatre," co-star Lucy Liu has said.
Tarantino said on Monday: "You go to a movie theatre with this and 500 other people, let them lock the door on you, shut off the lights, turn on the projector and you will be taking a tiptoe through the tulips with my brain."
Thurman, who spends much of the film in a yellow catsuit with a samurai sword, said she had found making the film very difficult.
It has received rave reviews in the US, though critics have also warned of the strong violence and gore.
'Outrageous and crazy'
"I was scared of every single fight that I was gonna have to encounter," she said.
She said the film's last battle scene, where she battles 88 Asian gangsters was "so outrageous and so crazy and so never ending that once I'd survived that, I literally walked outside and practically fell on my knees".
The film has been cut in half to form two movies
Thurman said her role had been "very lean", with little dialogue, and that she had had to learn how to fight with a samurai sword. She began training only six weeks after the birth of her second child.
"Every single day was hard because my character gets beaten up, tortured, murdered pummelled, and then I have to fight hundreds of guys... it was crazy," she told GMTV.
The film marks the return of Reservoir Dogs and Pulp Fiction director Tarantino after six years. His last film was 1997's poorly-received Jackie Brown.
The film also stars Daryl Hannah and Reservoir Dogs actor Michael Madsen, who also attended the opening.