The inclusion of child nudity has been frequently raised as morally problematic consequently, this book remains on lists of books either challenged or banned. As a result, the book proved controversial in the United States on its release and has continued to be so. Some also interpret sexual innuendo in the events, with the nudity, free-flowing milky fluids, and a giant (allegedly phallic) milk bottle. Critics object to Mickey's nudity which depicts not only his buttocks, but also his genitals. When Mickey (who looks to be about three years old) enters the Night Kitchen, he loses his pajamas and is fully naked in some parts of the story. It is then stated that 'thanks to Mickey, we have cake every morning', as he is shown holding a normal-sized milk bottle proudly while in his batter suit. With dawn breaking, the naked Mickey crows like a rooster and slides down the side of the bottle, back into his bed, where he is clothed again, 'cake-free and dried'. After his covering of batter disintegrates, making him naked again, he pours the needed milk in a cascade down to the bakers who joyfully finish making their morning cake. Upon reaching the bottle's opening, he dives in and briefly revels in the liquid. To make up for the baking ingredient deficiency, Mickey (now wearing a body suit of batter from the neck down) constructs an airplane out of bread dough so he can use the measuring cup as a hat and fly to the mouth of a gigantic milk bottle. Just before the baking pan is placed into the oven, the boy emerges from the pan, protesting that he is not the batter's milk.

While Mickey is buried in the mass, three identical bakers (who closely resemble Oliver Hardy) mix the batter and prepare it for baking, unaware (or unconcerned) that there is a little boy inside. He falls naked into a giant mixing pot that contains the batter for the 'morning cake'.

Suddenly, he begins to float, and loses all of his clothes as he drifts into a surreal world called the 'Night Kitchen'. The main character is a young boy named Mickey who, while sleeping in his bed, is disturbed by noise on a lower floor. The book drew controversy in the US due to depictions of nudity. It was adapted into a five-minute animated short film on Janudirected by Gene Deitch and released by Weston Woods. It was a Caldecott Honor recipient in 1971. In the Night Kitchen has been described by Sendak as part of a trilogy of books based on psychological development from In the Night Kitchen (toddler) to Where the Wild Things Are (pre-school) to Outside Over There (pre-adolescent). The book depicts a young boy's dream journey through a surreal baker's kitchen where he assists in the creation of a cake to be ready by the morning. In the Night Kitchen is a children's picture book written and illustrated by Maurice Sendak, first published in hardcover in 1970 by Harper and Row.

In the night kitchen first edition