Sportswriter and sports radio personality Oscar Madison, who is recently divorced, is about to hook up with neighbor Casey when he is visited by his old college pal, Felix Unger, whose wife has just thrown him out. Felix soon learns that his ex has hired a lawyer and plans to serve him with divorce papers. The neurotic, fussy Felix meets Casey's sister, the equally neurotic Emily, whose ex-husband left her for a man. Oscar plans a double date for the four of them, but Felix insists he won't be getting over his ex anytime soon. After viewing a slide show with Felix from their married days, however, it is Oscar who gets emotional and realizes he also is not fully over his break-up.