Objective To evaluate the effect of minimally invasive dynamic hip screws (MIDHS) in treating aged intertrochanteric fractures. Methods From April 2006 to March 2008, 49 aged patients with intertrochanteric fractures were treated with MIDHS. There were 22 males and 27 females, aged 65-78 years (average 70.2 years). Frature was caused by trafficaccident in 7 cases, by fall ing from height in 3 cases, and by injury from fall in 39 cases. The time from injury to operation was 2-12 days (average 5.5 days). According to Evans classification, there were 28 cases of types I, II (stable fracture) and 21 cases of types III, IV (unstable fracture). If the Singh index≤3 was defined as osteoporosis, the osteoporotic rate was 71.4% (35/49). All patients were on a radiolucent fracture traction table and their fractures had satisfactory closed reduction. After the guide wire was inserted and reamed under fluoroscopy, the lag screw and side plate were introduced through the small incision. In all unstable fractures, an additional, antirotational and large cancellous bone screw was used cranial to the DHS. Results The average operation time was 65.2 minutes. The average blood loss was 189.3 mL. All patients had satisfactory reduction and 79.6% (39/49) had adequate lag screw positions. The average postoperative hospital ization days was 5.8 days (3-12 days). All incision healed at stage I. There was no postoperative complications. Forty-nine patients were followed up 12 to 30 months (average 19.8 months). Fractures healed within 16 weeks in 47 patients and the average healing time was 13.1 weeks (12-16 weeks). The average Harris scoring was 90.8 (75-95). Implant failure and nonunion occurred in 2 cases, no serious compl ication occurred in other patients. Conclusion The MIDHS is a simple, safe and effective method for treatment of aged intertrochanteric fractures.