ABSTRACT Background: Fracture shaft humerus make up to approximately 1% of all fractures. Surgeons are now trying to balance the disadvantages of conservative and operative management by minimal surgical intervention (biological fixation by closed intramedullary nailing). The present study was aimed to study antegrade interlocking intramedullary nailing of the humerus in adults. Material and Methods: Present study was hospital based, prospective & observational study, conducted in patients > 18years, either gender, with fresh fracture shaft of humerus underwent antegrade interlocking intramedullary nailing of the humerus. Results: Out of 30 patients, commonest age group affected was between 31 to 40 years (30%). Majority of patients 12(40%) had simple transverse type of fracture followed by bending wedge fracture in 7(23.33%) patients. Majority of patients 15 (50.00%) were operated on due to associated multiple injuries of the axial or appendicle skeleton, 23(76.67%) Acute fracture, 1(3.33%) delayed unions, 4 non-union and 2 pathological fractures were treated. There were 25(83.33%) closed fractures and 5(16.67%) open fractures at admission. The commonest associated injury was trauma to the contralateral Colle’s fracture 4 (2 1%) femoral shaft fracture 4 (13.2) followed by associated juries to the appendicular or axial skeleton. Excellent to good results were seen in 93.33% patients. Out of the 30 cases followed up, one patient had pain in the shoulder in abduction and forward flexion, symptoms of the impingement syndrome which were relieved after removal of implant. All 4 cases of radial nerve palsy had excellent function return at the end of 6 months. Conclusion: Management of fracture shaft humerus by the antegrade interlocking nail in adults had advantages of a closed over an open procedure are, short operative time, immediate postoperative mobilization of patient, the biomechanical advantages and low complication rate.