【Abstract】 Objective To evaluate the cl inical outcome of free vascularized fibular associated with il iac graft intreatment of old femoral neck fracture. Methods From January 1994 to January 1997, 76 cases of old femoral neck fracture were treated with free vascularized fibular associated with il iac graft, including 54 males and 22 females, aging from 24 to 48 years with an average of 31.5 years. All of these fractures resulted from injury. There were 20 cases of Garden II, 41 of Garden III and 15 of Garden IV. Based on the location of fracture, there was 26 cases of subcapital, 42 cases of transcervical and 8 cases of basal. Sixty-five cases were treated with internal fixation, 7 cases with skin traction and 4 just with staying in bed. Their Harris score were from 52 to 72 with an average of 65.6. The time from injury to operation was 2-24 months. The size of free vascularized fibular was 6-8 cm and il iac graft was 3.0 cm×2.0 cm×1.5 cm. Results In 76 cases, 68 were followed up and all fractures healed within 4 to 6 months with an average of 5.2 months. The increased density in femoral head was observed 1 year after operation. After 10 years of operation, normal hip function was achieved in 63 cases（followed up 10.1 -12.4 years with theaverage as 10.5 years); the Harris score was 87.5 (84 to 94). The structure of femoral head was normal and the grafted fibular and il iac bone healed with the femoral, no elapse or cyst occurred. Five cases had been compl ied with total hip replacement for femoral head necrosis or other. Conclusion Free vascularized fibular associated with il iac graft is a good method to treat old femoral neck fracture.