“Tropic Thunder” is pushing the envelope too far for groups representing the mentally disabled.

Dozens of people from organizations such as the Special Olympics and the American Association of People with Disabilities protested the movie-industry spoof across the street from the film’s Los Angeles premiere at Mann’s Bruin Theatre on Monday. The protesters held up signs with slogans such as “Call me by my name, not by my label” and chanted phrases such as “Ban the movie, ban the word.”

The groups are outraged over scenes featuring the liberal usage of a disparaging term used to describe the mentally disabled. In the movie, director and co-star Ben Stiller plays a fame-hungry actor cast in a war movie who previously had a role as a mentally disabled character named Simple Jack. The DreamWorks film, which opens Wednesday, also stars Robert Downey Jr. and Jack Black.

“When I heard about it, I felt really hurt inside,” Special Olympics global messenger Dustin Plunkett said. “I cannot believe a writer could write something like that. It’s not the way that we want to be portrayed. We have feelings. We don’t like the word retard. We are people. We’re just like any other people out there. We want to be ourselves and not be discriminated against.”

Andrew J. Imparato, president of the American Association of People with Disabilities, said he and other representatives from advocacy groups representing the mentally disabled met with DreamWorks co-chairwoman Stacey Snider and watched a private screening of the film Monday morning. Mr. Imparato called the movie “tasteless” and said it was “offensive start to finish.”

“I have a sense of humor,” Mr. Imparato said. “There were parts of the movie where I laughed, but it seems to me that the movie tried really hard to go too far and then pull back on everything that was offensive except the issue of people with intellectual disabilities. I just think Ben Stiller and the people involved in this movie just didn’t think it was going to be offensive.”

Following the original complaints from the advocacy groups, DreamWorks pulled some promotional materials, including a Web site that promoted the film-within-a-film starring Mr. Stiller’s character, which contained the tag line “Once there was a retard.” DreamWorks spokesman Chip Sullivan previously said in a statement that “no changes or cuts to the film will be made.”

“If you want to pick on people, as the old playground saying goes, pick on people your own size,” Timothy Shriver, chairman of the Special Olympics, said. He is calling for a boycott of “Tropic Thunder” along with the other groups. “This population struggles too much with the basics to have to struggle against Hollywood. We’re sending a message that this hate speech is no longer acceptable.”