Two lovers are shown lying next to each other on a bed, with their bare backs visible. Sex is implied, but nothing explicit is shown.

Boys fight each other.

A boy jabs his foster mother's left arm with a knife - later her arm is seen with a mild amount of blood near the cut.

Two people are hit near the head with a baseball bat - both assaults are off-screen, but the noise is audible.

Brief strong language (e.g. one use of "shit" and one use of "fuck.")

Some teenagers smoke.

A few scenes in which characters smoke.

One scene in which a character drinks beer.

The film's titular character has a tense home situation. There are multiple scenes in which he tries to escape from legal guardians, either by running or by bike.

The Kid with a Bike doesn't have explicit content. The themes of rebellion and adoption may be emotional for some viewers, but sex and violence are almost entirely off-screen.