Humeral shaft fractures are commonly seen orthopaedics injuries. Open reduction with internal fixation (ORIF) with plating is a gold standard procedure despite various issues such as infection, radial nerve palsy and no-nunion. Close reduction with
interlocking nails (ILN) is not a very popular procedure. Therefore, it is of interest to collect data on the significance of interlocking nail in different pattern of humerus shaft fracture. 30 patients with closed humeral shaft fracture participated
in this study. The fractures were classified according to their descriptive location as proximal, middle and distal. All surgeries were performed by a single surgeon familiar with the ILN procedure. All patients had appropriate clinical, radiological
and pre and postoperative assessment. Data on patients were collected at 2, 6weeks, 12weeks, 18 weeks and 6 months. 19 cases with middle third and distal third fractures were united within 10-14 weeks. 6 cases of proximal shaft fracture were united in
14-18 weeks. According to Rodrı ´guez–Merchant criteria - Middle shaft fracture has shown good results (n=9, 75%) followed by distal third shaft fracture (n=6, 60%) and proximal third fracture (n=1, 12.5%). Though there is decrease in mean ASES score
in all three groups of fractures but the Mid shaft fracture has shown significant decline in ASES score suggesting improvement in pain and ROM after 6 months. Thus, ILN of humerus is a simple and a safe procedure for treating fractures of middle and
distal third shaft humerus. However, this study does not support ILN for the management of proximal third humerus fracture.