Background: To assess the functional outcome of three or four part fracture treated surgically with proximal humerus internal locking system (PHILOS). Materials & methods: 20 Patients diagnosed of three and four part proximal humerus fracture were admitted and fitness for anesthesia was done. Preoperative True Anteroposterior, lateral radiographs(Y view) in scapular plane along with CT scan was done as per the standard protocol of care. After complete informed consent and ethics committee approval study was started. Functional Outcome was assessed with by Disability of Arm, Shoulder and hand Score (DASH score). DASH score is measured from 0 (no disability) to 100 (most severe diability) Patient was not called especially for evaluating scores and radiographs, all the procedure were done during routine check-ups. Results: Mean DASH score at 3 months and 6 months was 39.1 and 23.5 respectively. Significant results were obtained while comparing the mean DASH at different follow-up time intervals. According to DASH score, “No problem”, “Problem, but working” and “Unable to work” was observed in 60 percent, 25 percent and 15 percent of the patients respectively. Implant failure, infection and malunion were seen in 5 percent of the patients. Conclusion: Fractures of the proximal humerus especially three and four part fractures have been a difficult group to treat. Good functional outcome was achieved in this group of patients using PHILOS. Key words: Proximal humerus internal locking system (PHILOS), Fracture, Proximal Humerus