Six children with entrapment of the medial epicondyle in the elbow after closed reduction of a posterior dislocation were seen an average of 14 weeks after injury. The elbows were painful and the average range of flexion was 22 degrees. Two children had ulnar nerve involvement which recovered after operation. The epicondyle was removed from the joint and either reattached to the humerus or excised, and the muscles reattached. Two children had anterior transposition of the ulnar nerve, one for pre-operative hyperaesthesia, and the other to relieve tension on the nerve. At follow-up, at an average of 15 months after operation, flexion had increased fivefold, none of the children had pain and all were leading normal lives.