Melvin Udall is the most dysfunctional of men, an acid-tongued romance novelist who suffers from obsessive-compulsive disorder. As part of Melvin's unwavering daily routine, he consumes an artery-hardening breakfast of bacon, sausages and eggs at a local cafe. The only waitress willing to stand up to his sarcastic tirades is Carol Connelly, a single mother struggling to raise her chronically asthmatic son.

Simon Nye has the distinct misfortune of living across the hall from Melvin. A talented artist, Simon is the darling of New York's art world, reason enough to draw Melvin's verbal fire.

These three, none of whom has a chance in hell of finding real happiness, discover their fates intertwined because of a fourth character: an ugly little dog named Verdall.