This retrospective study included four patients with transfemoral amputations who had undergone six lengthenings of their residual femurs. Initial femoral bone lengths averaged 15.5 cm with a mean final length of 21 cm. The average gain of limb length (ischium to end of soft tissue), however, was 2 cm (15%). Second lengthenings resulted in only 17% additional bone length, compared to 50% for first lengthenings. Treatment time was protracted and complications resulted from infection, bone healing, and pin migration. However, all patients reported substantial improvement in walking function and prosthetic use.