CAT ON A HOT TIN ROOF is a story of an affluent Southerner, Big Daddy Pollitt, who is dying of cancer. The family gathers at the Mississippi mansion for his birthday, aware that this may be his last. Big Daddy does not know, however, because the family doctor, eldest son Gooper, and his wife, Mae, decide to keep the fact concealed from him. Two other family members join the clan for the party, Brick, the youngest Pollitt, and his beautiful wife, Maggie.

Gooper and Brick are the only heirs to Big Daddy's enormous estate, and Gooper is well aware that Brick is the favorite son. In an effort to win Big Daddy over, Gooper and Mae make a display of themselves and their children, hoping the patriarch will notice that they will provide heirs for the estate. They are out to discredit Brick and Maggie, who do not have children. Brick seems destined to live the rest of his life in a drunken stupor.

Maggie is on to Gooper and Mae's plan and approaches her husband about it. Explaining their scheme to steal away the family fortune, Maggie begs Brick to make love to her, but he suspects she has been unfaithful to him and refuses.

Brick, who has broken his leg in a drunken attempt to relive his youth, is on crutches throughout the film and keeps to his room during the visit. Obviously racked with inner pain, Brick drinks steadily and is filled with remorse and guilt over the suicide of his best friend, Skipper, whom he idolized. Skipper had called Brick in a desperate cry for help and Brick had refused his pleas.

In a dramatic interplay between father and son, Big Daddy forces this admission out of Brick. Lashing back for bringing his emotions to the surface, Brick spits out the truth about Big Daddy's cancer. Later, in a desperate attempt to help Brick, Maggie announces to Big Daddy that she's pregnant. It's a lie, of course, but Brick is touched by her loyalty to him. The conversation between he and his father seems to have expelled the fog that he's hidden in for so long, and he's ready to confront life again. Maggie's outpouring of love prompts him to make good on her blatant lie, and the film closes with their passionate kiss.