The authors have conducted a clinical and biomechanical study of blind nailing of trochanteric fractures by the Ender's technique. The nail is introduced through the medial femoral condyle. The study was based on 120 operations. From the biomechanical standpoint, the authors studied the forces exerted in the medullary canal of the femoral shaft and the grip of the nail in the head and neck of the femur. In most of the cases the technique allowed immediate walking with weight-bearing. The results are compared with those obtained after nail-plate fixation. They were superior on three counts--less infection, less breakage of inserted material and less non-union, but the technique produced more mal-union. For this reason, the authors consider it to be an excellent technique but to be reserved for older patients.