The play takes place in the living room of a middle-aged couple, George and Martha, on a New England college campus in the 1960s. George is a history professor and Martha is the daughter of the college president. After returning home from a party at Martha's father's house, slightly intoxicated, they invite a younger couple, Nick (a biology professor) and his wife Honey, over for drinks.
Throughout the play, George and Martha engage in a series of psychological games, including a game of "humiliating the guests" and a game of "making up stories." As the night wears on, the couple's verbal sparring matches become increasingly intense and personal, exposing their deep-seated insecurities and the underlying tensions in their marriage. The secrets of both couples are laid bare and illusions are exposed.
In a climactic moment, George decides to "kill" the imaginary son he and Martha have invented to compensate for their childlessness. This forces George and Martha to finally face the truth about their marriage.
In the quiet ending, they stand together, sharing their sorrow.