Fractures of the proximal forearm in young children may be unstable with the elbow flexed but stable with it in extension. Fifteen such fractures were managed by immobilisation in long-arm casts with the elbow extended. Only one patient had more than 15 degrees angulation at the time of bony union. All obtained normal elbow movement at two weeks and full forearm rotation at follow-up. No casts fell off. The extended elbow cast is awkward but it provides an alternative to internal fixation for some unstable fractures.