West Side Story

 When filming her final scene in "West Side Story" (1961) in which her character Anita is harassed and nearly raped by New York street gang members the Jets, Rita Moreno was reduced to tears, as it brought flashbacks of similar real-life childhood experiences. When she broke down, the other actors in the scene immediately stopped to comfort her and help her get through the scene.

Moreno stated that her line reading of "Don't you touch me!" after the Jets attack Anita was her imitating Marlon Brando, her then-boyfriend. Brando even noticed at the film's premiere.

Moreno's singing voice was dubbed by Betty Wand only for "A Boy Like That" since it was below her range. Moreno sang "America" herself. Marni Nixon (who dubbed for Natalie Wood) had to do the end of the quintet for Moreno. The reason was that Wand and Moreno both had colds and could not sing, so the filmmakers asked Nixon to do the end. So Nixon is singing two voices at once.

Moreno won the Academy Award for Best Supporting Actress for "West Side Story," a 1972 Grammy Award for her contribution to "The Electric Company"'s soundtrack album, followed that up three years later with a Tony Award as Best Featured Actress in a Musical for "The Ritz" (a role she would reprise in the 1976 film version), and also won Emmy Awards for "The Muppet Show" and "The Rockford Files."

Moreno once held the record to win all four EGOT awards in the shortest amount of time, within a 16-year time frame (from 1962 to 1977. This record was broken by composer Robert Lopez in 2014, when he won an Oscar for writing "Let it Go" for "Frozen" to complete his EGOT. He achieved the feat in a 10-year time frame.