The development of the locking plate has allowed considerable progress in the treatment of fractures, but few studies have evaluated its usefulness for the treatment of aseptic non-union. We have treated 15 cases of aseptic non-union of long bones in the lower limb (femur : 5, tibia : 10, including 3 periprosthetic non-unions) using locking plates. The initial treatments were external fixation in 1 case, intramedullary nailing in 2, conventional plating in 5, locking plating in 4, and use of a cast only in 3. Nine cases were hypertrophic non-unions and 5 were atrophic non-unions. Union was achieved in all cases, although one case showed correction loss and 5 showed delayed union. These results were quite good, and allowed us to conclude that the locking plate is useful for the treatment of aseptic non-union of bones in the lower limb. Because the degree of bone defect and deformity differs in individual cases, detailed preoperative planning and choice of an appropriate operative technique are needed to achieve good results.