The results of treatment of 10 both-bone unstable diaphyseal fractures of the forearm in children by open-reduction and intramedullary fixation with Kirschner wiring of the radius are presented. All fractured healed in perfect alignment. No complications occurred. In a 3 year and 2 month follow-up all the patients had excellent results with full range of movement. The advantages of this method are: a) it is easy to carry out; b) it maintains anatomical reduction; c) a second operation to remove the internal fixation device is not required; d) fixation of the ulna is not necessary, because in all patients a realignment of the ulnar fragments occurred after radius reduction.