From June 1996 to February 1998, we reviewed the cases of 27 patients who had a displaced - extension type supracondylar fracture of the humerus retrospectively. The mean length of follow-up was 1.3 years. According to Gartland classification, type II was 7 cases (26%), type III-A was 11 cases (41%), type III-B was 9 cases (33%). We treated with three different methods, including closed reduction and percutaneous Kirschner-wire fixation, skeletal traction, and cast application after closed reduction. In type II fractures, we used two parallel lateral pins. In type III fractures, we used 2 lateral parallel pins followed by 1 medial crossed pin predominantly. The results of treatment were assessed using the criteria of Flynn et al. We graded cosmetic and functional factors separately. Satisfactory results were achieved by percutaneous K-wire fixation(96%). There were seven neural lesions. These were the result of injury and not of the treatment, with exception of one case. Neural injuries spontaneously resolved at a mean of 2.5 months(range 1.5 to 5 months) after injury. Varus deformity was present in one patient. There was no Volkman's ischemic contracture. Percutaneous Kirschnerwire fixation is advocated as the method of choice for the majority of displaced-extension type supracondylar humerus fractures in children.