Corrective osteotomy of the distal humerus for a posttraumatic cubitus varus was performed in 31 patients using a modified step-cut osteotomy. The average patient age was 14.3 years. Complete bony union was obtained between the 8th and 16th weeks. Twenty-one patients achieved excellent results, 7 achieved good results, and 3 achieved poor results on the basis of Oppenheim's criteria. Although the results for 28 patients (90.3%) were classified as excellent or good, 6 patients (19.3%) were subjectively disappointed due to bulging of the lateral condyle. We achieved an overall improvement in mechanical stability and established an easier technique in corrective osteotomy. However, this approach may not be appropriate if the correction angle desired is greater than 30°.