We analysed the operative technique, morbidity and functional outcome of osteotomy and plate fixation for malunited fractures of the forearm sustained in childhood. A total of 20 consecutive patients underwent corrective osteotomy of 21 malunited fractures at a mean age of 12 years (4 to 25). The mean time between the injury and the osteotomy was 30 months (2 to 140). After removal of the plate, one patient suffered transient dysaesthesia of the superficial radial nerve. The mean gain in the range of movement was 85 degrees (20 degrees to 140 degrees ). The interval between injury and osteotomy, and the age at osteotomy significantly influenced the functional outcome (p=0.011 and p=0.004, respectively). Malunited fractures of the forearm sustained in childhood can be adequately treated by osteotomy and plate fixation with excellent functional results and minimal complications. In the case of established malunion it is advisable to perform corrective osteotomy without delay.