Following the collapse of his marriage, TV newswriter Felix Ungar decides to commit suicide in a cheap hotel room near Times Square. He fails at even this, however, and dejectedly makes his way to the weekly poker game being held at the Riverside Drive apartment of his best friend, Oscar Madison, a divorced sportswriter. Felix accepts an invitation to share the 8-room apartment, but his hypochondria and his compulsion for order and cleanliness drive the slovenly Oscar to distraction, and the two men are soon quarreling. Eventually, Oscar suggests they double-date Cecily and Gwendolyn Pigeon, two giddy English sisters who also live in the building, and Felix agrees on the condition that he be permitted to cook dinner. The evening ends disastrously when Felix's meatloaf burns, and he breaks down into a sobbing account of his broken marriage that elicits sympathetic tears from the Pigeon sisters. Finally, Felix's refusal to accompany the women upstairs so enrages Oscar that he restores his apartment to its original disorder and throws Felix out. After Felix departs, the card-playing cronies turn on Oscar and criticize his harsh treatment of their friend. They conduct a futile search for Felix, but he suddenly reappears and announces that he is moving in with Cecily and Gwendolyn until he can straighten out his life. Once Felix has left, the "boys" sit down for their weekly poker game, and they are surprised when Oscar rebukes them for spilling ashes on the table.