In this study is a series of 30 cases of traumatic closed fracture of humerus shaft treated with closed antegrade intramedullary interlocking nailing and were followed up to register the clinical and radiological outcome and complications, its advantages and disadvantages were studied. Methods: Our prospective study is a series of 30 cases of traumatic closed fracture of humerus shaft without any neurovascular injury either simple, wedge or complex types and treated with closed antegrade intramedullary interlocking nailing. This study is to be conducted over a period from December 2017 to May 2019 Cases were followed up for 6 months and the short term functional results were analysed by using Constant and Murley score, ASES score. Results: Most common fracture pattern is transverse & oblique type. Mean radiological union in weeks was 13.97 There was no non union in our study. There were no instances infection. There was 1 case of delayed union which was treated by bone marrow injection at fracture site. Good or full range of mobility of shoulder & elbow joints was present in 25 patients.5 patients had poor or painfully restricted movement due to shoulder impingement. Conclusion: Humerus intramedullary nailing technique is an excellent, least invasive surgical option available to manage humeral shaft fractures with early fracture consolidation and better union rates with advantages including minimal surgical exposure, better biological fixation, Minimal disturbances of soft tissues and early mobilization of neighboring joints, less chance of radial nerve injury.