Eighty-three lengthening procedures were performed in 71 patients with congenital shortening of the lower limb. Mean lengthening achieved was 7 cm, which represented a mean increase of 24% of the initial bone length. Seventy-nine percent of patients had at least one preexisting joint deformity or instability. The devices used and the bone lengthened for the 83 procedures were divided into three groups. Fifty-one femurs (Group I) and 18 tibiae (Group II) were lengthened using the Wagner device, and 14 tibiae (Group III) were lengthened using the Ilizarov device. The final goal of lengthening was rated as good, fair, or poor. Good results were obtained in 55% of the procedures, fair results in 33%, and poor results in 12%. Poor results were most frequent in Group I (18%), whereas no poor result was reported in Group III. Complications occurred in 77% of patients. No significant difference could be demonstrated in the complication incidence of Groups II and III. Complications were significantly more frequent and results generally poorer when the lengthening exceeded 25% of the initial bone length or when the femur was lengthened.