To develop a novel modification of an existing technique Using trigonometry a procedure for accurately measuring the rotational alignment of the proximal femur was devised. This technique was performed on the fracture table with standard image intensification views and required a series of simple calculations. With the knowledge of the proximal rotational geometry of the femur the fractures were fixed according to normative data of femoral neck anteversion. The clinical correlation was then assessed. The development of the technique was successful. It was clinically practical and was associated with accurate rotational alignment in patients after intramedullary nailing of femoral fractures. This method was seen to be a useful adjunct to current nailing techniques with both educational and clinical benefits. The described technique has clinical application and may help surgeons avoid rotation al malalignment when undertaking intramedullary nailing of fractures of the femur.