This paper reports 72 cases of genu varum treated by a U-shaped osteotomy of the tibia and an oblique osteotomy of the fibula in combination with immobilization effected by a specially designed external tibial fixator. Owing to this modified approach, the patients were able to stand up and move about much earlier than usual. Our trial yielded 80.7% excellent, 16.6% good and 2.7% fair results. The treatment course was shortened to two thirds of the time required when using previously described techniques.