Objective To compare the effectiveness of the proximal femoral nail anti-rotation (PFNA) and locking compression plate (LCP) in the treatment of intertrochanteric fractures with the lateral unsubstantial femoral wall in elderly patients. Methods Between May 2009 and August 2012, 69 elderly patients with intertrochanteric fractures with the lateral unsubstantial femoral wall were treated. Fractures were fixed with PFNA in 36 patients (PFNA group), and with LCP in 33 patients (LCP group). There was no significant difference in gender, age, injury cause, side of fracture, and fracture AO type between 2 groups (P > 0.05). The incision length, operation time, intraoperative blood loss, total blood loss, fluoroscopy frequency, time for ambulation, and early (within 3 months) and late (more than 12 months) complications were compared. Fracture healing was assessed according to X-ray reexamination, the function of the hip joint was assessed according to the Harris hip scoring system. Results The incision length, operation time, intraoperative blood loss, and time for ambulation of PFNA group were significantly less than those of LCP group (P < 0.05), but the fluoroscopy frequency of PFNA group was significantly more than that of LCP group (P < 0.05). There was no significant difference in total blood loss between 2 groups (t=-1.686, P=0.096). The patients were followed up 12-24 months in PFNA group and 15-30 months in LCP group. The X-ray reexamination revealed fracture healing at (12.667±2.527) weeks in patients of PFNA group, and at (13.364±1.194) weeks in the others of LCP group except 1 case of nonunion, showing no significant difference (t=-1.443, P=0.154). There was no significant difference in Harris hip score between PFNA group (84.611±7.076) and LCP group (81.785±7.500) at 12 months after operation (t=1.626, P=0.109). The early complication rate and late complication rate were 16.7% (6/36) and 5.6% (2/36) in PFNA group and were 9.1% (3/33) and 9.1% (3/33) in LCP group, all showing no significant difference between 2 groups (χ2=0.871, P=0.481; χ2=0.320, P=0.665). Conclusion Both PFNA and LCP have good effectiveness in the treatment of intertrochanteric fractures with the lateral unsubstantial femoral wall in the elderly patients. Each has its own advantages and disadvantages.