Orthopaedic practitioners encounter the most usual fracture known as Subtrochanteric femoral fracturesoften are associated with intertrochanteric fractureswithin 5 centimeters distal to the lesser trochanter. It is difficult to treat due to strong deforming forces at the fracture site, tenuous blood supply, and the immense load-bearing forces exerted through the peri-trochanteric region. Adequate reduction and stable fixation are paramount when treating these fractures to optimize patient outcomes. Hence, it is essential to evaluate functional outcome of subtrochanteric fracture treated by proximal femur nail. We included 30 patients with close subtrochanteric fracture were treated with proximal femur nail. All patients were follow-up in OPD on 15th day, then every month and progress of union seen in x-ray. Harris – hip score calculated at each visit. Data collected was subjected to statistical analysis. Majority of cases were males 70% and female were 30% and majority of cases N=14(46%) were found in the 18-40 years of age range. Mode of injury by road traffic accidents were higher 23(76.67%) and 17(56.67%) patients had left side injury. Radiological findings according to Seinsheimer Classification majorly patients fell under type II B (27.4%) fractures. Based on Harris Hip score, 4 (13.33%) patient’s outcome was excellent, 22 (72.6%) patients showed 12 weeks of union, 6 (20%) patients were with other injury and 25 (83%) cases have fracture reduced by close reduction. 10 (33.33%) patients had normal BMI which lies between 18.5 kg/m2-24.9 kg/m2 and 4 (13.33%) patients had Obesity class II 35.0 kg/m2-39.9 kg/m2 of BMI. 9 cases had Union time 12 weeks and no case have 14 weeks of union time in which BMI was between 25.0 kg/m2 - 29.9 kg/m2. 7 cases had Union time 12 weeks and 3 cases have 14 weeks of union time, in which BMI was between 18.5 kg/m2 – 24.9 kg/m2.The correlation between BMI status and Union Time was found to be statistically significant (P<0.05), on applying Chi- square test.Fractures were reduced by Close reduction among 25/30 (83%) patients. The proximal femoral nail is an excellent implant for femoral subtrochanteric fracturesparticularly in the elders.