We start off with Max making mischief around the house until his mother scolds him and he threatens to eat her up. She sends him to bed without dinner and as Max fumes in his room, it turns into a huge forest. Max enters a small boat and as he sails it, he is led to the land of the Wild Things, a race of huge, furry, troll-like monsters who prepare to eat him. He tames the Wild Things and they make him his king. They rumpus around the forest until Max tells them to stop and sends them to bed without their supper. Realizing he is lonely, he starts to feel homesick and must return home, so he gives up being king of the Wild things. Max decides to return home, only to find his supper waiting and it is still hot.
Nine-year-old Max is misunderstood by his mother and his older sister, Claire. We begin with our young hero playing in his makeshift igloo until Claire and her friends make the mistake of smashing it. Out of anger, Max messes up his sister's room and his fury turns to remorse after tearing up a valentine heart he gave to her.
At dinnertime, Max tells his mother a story about a vampire who is shunned by his friends after breaking his fangs on a building. At school, he is told the sun is going to vanish. The next dinnertime, Max comes down to play with his mother, but she is having a boyfriend. Things get worse when Max lashes out at her and demands to be fed. His mother sends him to his room without supper, but, in a fit of rage, Max throws a hissy-fit and bites her on the shoulder. She yells at him for his behavior and Max, realizing that this time he crossed the line, runs away from home in shame.
Max discovers a boat and goes onto it. The currents pull him into the land of the Wild Things. The huge inhabitants - Carol, the leader, KW, the mother hen and Carol's love, Douglas, Carol's ally; Judith, the neighborhood grump, Ira, the lovable lug, Alexander, a goat, and The Bull, discover Max and prepare to eat him when he stops them in their tracks and tames them. Carol makes Max the king of all Wild Things and they have a huge rumpus.
Later, Max tells KW about his troubles and Carol shows him a special place for him. While spending time with his new friends, Max and the Wild Things have a dirt clod fight that goes belly-up. After a huge fight, Carol, out of anger, chases Max and is about to eat him when KW hides him in her huge stomach.
After a close call, Max discovers that Carol's tantrums have destroyed his home and he gives him a heart made out of twigs. Then he realizes that he must return home and face his mother, so he hops into his boat and rides home, howling a farewell to his friends.
As soon as Max returns home, he and his mother reconcile and he is rewarded with dinner.