A retrospective comparative study was done of two groups of patients with displaced supracondylar fractures of the humerus. The patients in the first group were treated with Dunlop's traction, while those in the second group were treated by percutaneous pin fixation. There were thirty-six patients in the group treated with Dunlop's traction, of whom twenty-seven were seen in follow-up with an average time of 2.7 years. Twenty-eight patients were in the group treated with pin fixation, of whom twenty were seen in follow-up with an average time of 2.9 years. In each case the chart and roentgenograms were reviewed and the patient was examined. The results showed a 33 per cent incidence of cubitus varus (so-called gunstock deformity) in the patients treated with Dunlop's traction as compared with 5 per cent in those pinned percutaneously. The range of elbow motion was also slightly better in the group treated with pin fixation. Furthermore, the costs and hospital stays were significantly less in those treated by pinning. Complications in both groups were few.