The entire cast of the show attended the red-carpet event Saturday night to promote the season premiere, which airs Wednesday. The show is filmed in Hawaii.
The crowd welcomed each cast member with loud cheers, and some fans got autographs.
Before the season's first episode was shown on the big screen, producers asked that the audience keep quiet about it until after it airs on TV, so as not to spoil the surprise for the rest of the fans.
Cast members said they were flattered by the reception.
"Believe it or not, this doesn't happen every day," said Terry O'Quinn, who plays Locke on the show. "I'm not used to it, but I don't mind it. I've never been to a Hollywood premiere, but can't imagine anything surpassing it."
In the Oct. 4 season premiere episode, titled "A Tale of Two Cities," Jack (Matthew Fox), Kate (Evangeline Lilly) and Sawyer (Josh Holloway) begin to discover what they are up against as prisoners of the island's other mysterious inhabitants, "The Others."