A method of closed unlocked femoral nailing using only ultrasound guidance from the beginning to end of the operation is described. The method was evaluated as a prospective study in 150 cases of unilateral uncomminuted or very minimal comminuted (Winquist I) femoral shaft fracture who could be operated on within one week. There were 132 males and 18 females whose ages ranged from 16 to 70 years (average, 26). The interval from injury to operation averaged 2.3 days (range, 1–7). Twenty seven cases were Winquist I comminution and 123 cases were non- comminuted fractures. Hundred and forty five cases (97%) were successful with the method with an average operation time of 35.8 minutes (range, 30–50). Of five failure cases; one had nail incarceration, one had accidentally torn flexible reamer and three were not able to pass the guide wire from the proximal femoral canal into the distal femoral canal within ten minutes. The ultrasound which is more available in most hospital and no radiation hazard can be used as an alternative method for monitoring the fracture alignment in closed unlocked femoral nailing with a very high succes rate. This method will be very helpful for the developing country where the C-arm image intensifier is not available.