Altman: Favours films dealing with human emotions
"Nobody would have thought to commit an atrocity like that unless they'd seen it in a movie," said Altman, who also directed MASH and The Player.
Violent blockbusters "taught them how to do it" and Hollywood must now stop showing mass destruction in movies, he said.
The 76-year-old Oscar-nominated director said violent action films with big explosions - usually targeted at young men - amount to training films for such bold attacks.
"How dare we continue to show this kind of mass destruction in movies?
"I just believe we created this atmosphere and taught them how to do it," he said.
A number of Hollywood productions have been changed, put back or scrapped since 11 September because of their similarities to events in America.
But that has been because film studios think the subject matter is now inappropriate - and not because they do not want to inspire further attacks.
'Grown-up films'
Altman hoped that the TV footage of the attacks and their aftermath will now make audiences prefer more thoughtful, character-based films.
"Maybe there's a chance to get back to... grown-up films - anything that uses humour and dramatic values to deal with human emotions and gets down to what people are to people," he said.
Gosford Park, starring Kristin Scott Thomas, Stephen Fry and Emily Watson, gets its world première at the London Film Festival on 7 November.
Meanwhile, one of Hollywood's biggest stars, Michael Douglas, has urged Americans to return to air travel after the hijack bombings.
"We are all nervous but I think you have to live your life," the actor said after flying from New York to Scotland to take part in a pro-am golf tournament.
Douglas, star of Wall Street, Basic Instinct and Traffic, has a home in Manhattan and was in the city at the time of the attacks.
"We encouraged everybody at that time to go to New York because they lost a lot of business," he told STV television.
"Hopefully things will pick up, but people have just got to get on with it. You can't live in fear."
The actor will be playing in the Dunhill Links golf tournament - which is held at three Scottish golf courses - alongside Samuel L Jackson, Hugh Grant and professional golfers from Thursday.