Femoral fractures in adults frequently need an extensive dissection for attainment of adequate internal fixation, frequently leading to nonunion, infection and derangement of joint motion. Retrograde IM nailing, compared to the conventional methods, has advantages of reducing periarticular soft tissue dissection and establishing a load sharing construct reducing hardware failure. The purpose of this study is to verify the advantages of retrograde IM nailing by retrospective evaluation of the results of adult femoral fractures treated by this technique. The matrials were 17 femoral fractures in 15 patients treated by retrograde IM nailing and followed up for more than 1 year. The fracture was located in the middle third of the shaft in 5 and distal third in 12. The latter consisted nf 6 cases of type Al, 4 cases of type A2 and 2 cases of type A3 by Miiller's classification. The results were as follows; 1) Fracture union was achieved at an average of 17.5 weeks. 2) Full range of knee motion was gained in 15/17 knees (88%). 3) Complication occurred in 2 knees. One nonunion and one angulatory malunion. 4) There was no infection, no femoral shortening or implant failure. In conclusion, retrograde IM nailing of adult femoral fracture is an effective method in selected cases such as far distal femoral fracture, ipsilateral femur neck and shaft fractures, floating knee, post-TKR femoral fracture and so on. The merits of this technique are rigid fixation which is difficult to obtain with others, no need of fracture table, short operative time and mimium blood loss. However, It has potential problems such as difficulty in insertion of proximal locking screw and need for an arthrotomy to remove hardware.