Introduction: Subtrochanteric fractures are femoral fractures that involve the lesser trochanter and extend distally up to 5 cm. These fractures account for 10% to 34% of all fractures. Civilization and modernization has brought certain problems along with its own benefits to the citizens of the world over. Aims: To evaluate the outcome of subtrochanteric fractures in adults managed by Proximal Femoral Nail; Materials and Methods: The Observation and Cross sectional study. This Study was conducted from October 2019 – September 2021 at Department of Orthopaedics. Agartala Government Medical College & GB Pant hospital and west Tripura. Total 30 patients were included in this study. Result: In our study, out of 30 patients, higher number of patients had full in Hip ROM at 9 months [26 (86.7%)] though it was statistically significant (p<0.0001) (z=6.2106). We found that, most of the patients had Excellent Functional Outcome at 6 months [25 (83.3%)] and Excellent Functional Outcome at 9 months [26 (86.7%)] which were statistically significant (p<0.0001). Conclusion: In our study, PFN is biomechanically sound and has advantages on collapse at fracture site as it is done mostly in closed method. PFN prevents excess collapse at fracture site and maintain the neck length and Most of the complications are seen due to surgeon and instruments related. They can be cut down by good pre-operative planning