<p><strong>Background</strong>: After femoral and tibia bone fractures, the humerus fracture is the third long bone fracture. The purpose of this study was to clinically evaluate the outcomes of treating humerus fractures with an KN-5H humerus nailing system. The fixation of humerus fracture especially shaft fractures from intramedullay humeral nail the clinical outcomes obtained from the retrospective study of humerus nailing system on humeral fracture is controversial feature in surgical technical research, follow-up factors, and implants.</p><p><strong>Methods: </strong>In this retrospective study of KN-5H humerus nailing system (KN-5H intramedullary cannulated humerus nail, KN-5H reconstruction nail, cannulated and KN-5H reconstruction cannulated intramedullary humerus nail) manufactured by the Kaulmed Pvt. Ltd. is used. The total 26 patients from which 11 males and 15 females between the age group of 18-70 years with humerus fracture were taken. Patients didn't received conservative management. The fractures were categorized based on AO classification and Neer type. Th post-operative clinical effectiveness was evaluated using the Radiological evaluation, VAS score and Functional ROM results.</p><p><strong>Results: </strong>The mean follow-up period was 15 months (range 13 to 24 months). The mean time of union was 14 weeks (range 10 to 18 weeks) in 26 patients. No non-union occurred in any patients. Functional end results of shoulder and elbow were excellent in 92.3% patients, moderate 5.75% patients and poor in 1.95% patients. Postoperative complications included one superficial infection, 3 patients had nail impingement complain, one patient has shoulder stiffness and had pain in adduction. No implant related complication was reported.</p><p><strong>Conclusions: </strong>The treatment of proximal and diaphysis humerus fracture is highly recommended using intramedullary humeral nailing due to lower post-operative complication with high union rate. <strong></strong></p>