INTRODUCTIONThe humeral shaft cylindrical in shape, the expanse between the proximal insertion of the pectoralis major and the distal metaphyseal flare of the humerus, adds resistance to both torsional and bending forces and provides strength. Adequate soft tissue envelope favors good prognosis in healing of uncomplicated fractures.Humeral shaft fractures account for approximately 1-3% of all fractures and 20% of humeral fractures with a bimodal distribution with peaks in young male patients, 21-30 years of age, and a larger peak in older females from 60-80 years of age.1 Most humeral diaphysis fractures are simple patterns of the mid-diaphysis These fractures have potential to cause significant disability in the young which is often temporary and in the old often permanent disability.Plating or intramedullary nailing are the main surgical options available for the definitive primary management of closed humeral shaft fractures and have their respective proponents with no consensus. ABSTRACT Background: Humeral shaft fractures which account for approximately 1-3% of all fractures and 20% of humeral fractures have potential to cause significant disability in the young which is often temporary and in the old often permanent disability. The use of locked intramedullary nailing for the treatment of humeral shaft fractures is gaining popularity because of its biomechanical and biological advantages. Methods: We present a descriptive retrospective review of 20 consecutive patients with acute humeral shaft fractures treated using an antegrade interlocking nail. Fracture union, functional outcome measured with Constant-Murley shoulder score and American shoulder and elbow surgeons (ASES) shoulder score and complications were assessed. Results: Patient age ranged from 20 to 74 years (average, 36 years) and average follow-up was 30.7 months (range, 12-48 months). There were 13 male patients and 7 female patients. Fracture of the middle third was most common accounting to 80% (16/20) of the fractures. Fracture union was achieved in 90% (18/20) of our cases. 2 patients had nonunion for which secondary surgeries were needed. According to Constant-Murley score, shoulder function was excellent in 70% (14/20) and good in 25% (5/20). Average ASES score was 93.3%. None of the patients had radial nerve palsy postoperatively. Conclusions: Gentle progressive reaming, correct entry point, minimal damage to rotator cuff, properly embedding the tip of the nail, good apposition of fracture fragments, static locking will help make antegrade intramedullary nailing, a dependable solution for the treatment of humeral shaft fractures and in achieving successful union with preserved/good shoulder and elbow function.