A Streetcar Named Desire ends with the aftermath of Stanley’s climactic rape of Blanche. Stella, now a mother, has committed Blanche to a state-run mental institution, taking the rape accusation as evidence her sister has gone insane. What Stella doesn’t know is that Stanley’s violent and unjustifiable rape of Blanche has severed Blanche's already tenuous hold on reality. Blanche indeed seems delusional as she unwittingly leaves for the asylum in the midst of another of Stanley’s poker parties. This final scene neatly book-ends the play, which began with Blanche’s arrival and now concludes with her departure. In effect, Streetcar becomes the story of Blanche’s visit to the Kowalskis’ home. The central conflict of the play—the clashing of the world of Stanley and the world of Blanche—is resolved in Stanley’s favor. Life goes on, much as before, as the poker party indicates.

While the action of the ending is clear, its meaning is subject to different interpretations, dependent upon which character one feels is Streetcar’s hero. Those in Blanche’s camp see the play as a moral fable of a refined, delicate woman being broken down and driven mad by a brutish environment, personified by a bestial man. It thus ends with a triumph of the apes—dark, primitive forces that destroy anything they can’t understand. In contrast, those on Stanley’s side argue that Blanche, an unstable, unhealthy figure, is banished to her proper place after entering and disrupting a society. With her goes an obsolete, corrupt civilization, whose values, hypocritical morals, and pretensions have no place in a brave new democratic world. 

A third, more neutral, interpretation of the ending posits that the eventual outcome is not the fault of an individual but an inevitable result of a clash of cultures and classes. Williams himself once wrote of Streetcar, “I don’t want to focus guilt or blame on any one character but to have it a tragedy of misunderstanding and insensitivity to others.”

It's important to note that A Streetcar Named Desire has no published alternate endings, unlike some of Williams’ other works, such as Cat on a Hot Tin Roof. However, Williams collaborated on the screenplay of the 1951 film, which did make a significant change to the ending. As Blanche is led away, Stella abruptly decides to leave Stanley. The twist was dictated by the film industry, which demanded that Stanley be punished in some way for the rape. Subsequent film and TV versions have restored the original, bleaker ending, in which Stella remains with her husband.