In his biography of Elia Kazan, Richard Schickel describes how Kazan used a ploy to entice Marlon Brando to do the movie. He had Karl Malden direct a scene from the film with an up-and-coming fellow actor from the Actors Studio playing the Terry Malloy lead role. They figured the competitive Brando would not be eager to see such a major role handed to some new screen heartthrob. The ploy worked, especially since the competition had come in the form of a guy named Paul Newman.
As part of his contract, Marlon Brando only worked until 4:00 every day and then would leave to go see his analyst. Brando's mother had recently died and the conflicted young actor was in therapy to resolve his issues with his parents. Interestingly, for the film's classic scene between Rod Steiger and Brando in the back of the cab, all of Steiger's close-ups were filmed after Brando had left for the day, so Brando's lines were read by one of the crew members. For many years Steiger, who had actually stayed during Brando's close-ups to help him put in a better performance, remained very bitter that Brando didn't return the favor, and often mentioned it in interviews.
Shortly after the film's debut in 1954, the AFL-CIO expelled the East Coast longshoremen's union because it was still run by the mob.
In his autobiography, Marlon Brando revealed his initial thoughts about his performance. "On the day (Elia Kazan) showed me the completed picture, I was so depressed by my performance I got up and left the screening room. I thought I was a huge failure, and walked out without a word to him. I was simply embarrassed for myself."
The scene where Eva Marie Saint drops her glove and Marlon Brando picks it up and puts it on his hand was unplanned. Saint dropped her glove accidentally in rehearsal and Brando improvised the rest. Elia Kazan loved the new business and asked them to repeat it for the take.
Karl Malden: [name] At the hearing, Slim gives his name as "Mladen Sekulovich," Karl Malden's real name. Malden always deeply regretted having had to change his real, very ethnic name for the sake of his movie career, and attempted to make amends over the years by making sure his real name always showed up in his movies, one way or another.