The film is based on the popular Dutch childrens book by Chris van Abkoude. In a Dutch port in 1921 lives a 10-year-old orphan boy known to everyone simply as Little Crumb. His poverty-stricken mother Lize van Dien filled with shame was forced to turn him over to Mrs. Koster soon after he was born. Foster mother Mrs. Koster, who has cared for him since he was a baby, is very poor too, unable to support him by herself and proves to be a cruel taskmaster who insists Crumb bring her money before shell feed him. Somehow he must earn his keep out on the streets and can only go home after he has earned enough money. Crumb becomes an urchin stealing from the streets barrows and the shops to stay alive, sleeping in churches or huddled in doorways. Sometimes he has to run off from the police and he has earned the enmity of the most grownups around him.

A four-legged friend goes on a sailing vacation with his family. But then, due to a case of mistaken identity, they all end up in jail for burglary.