OBJECTIVE: To investigate the clinical efficacy of Proximal Femoral Nail Anti-rotation PFNA in the treatment of intertrochanteric fractures of the femur. METHODS: From January 2007 to January 2009, 44 cases of intertrochanteric femoral fractures were fixed with closed reduction PFNA. Results: All patients were followed up for 6-18 months, with a mean of 10 months, and all fractures healed in 11-23 weeks, with a mean of 13 weeks and a mean of 25 mm apical distance (TAD). 1 case of cerebral infarction recurred, and there were no complications such as infection, deep vein thrombosis, intramedullary nail fracture, femoral stem fracture, spiral blade loosening and breaking, and cutting out the femoral head. Conclusion: PFNA is an ideal intramedullary fixation system for treating intertrochanteric fractures of the femur because it has the advantages of simple operation steps, less bone loss, definite fracture fixation, less complications and early functional exercise for patients. Intraoperative control of TAD by measuring the sum of the distance from the caudal end of the guide pin to the articular surface (KAD) in the C-arm frontal position is important for the prevention of complications such as cutting out of the femoral head by the spiral blade.