Proximal humerus fractures have been a challenge to achieve stable fixation. PHILOS (Proximal Humerus internal locking system) is part of the latest generation of locking compression plates for proximal humeral fracture fixation. We aim to assess the clinical and functional outcome of proximal humeral fractures (2-part, 3-part and 4-part) treated with the PHILOS plate. We prospectively reviewed 50 patients who had a proximal humeral fracture treated with the PHILOS plate from September 2002 to September 2006 in our institution. Clinical outcome was measured using the patient-based Oxford shoulder and DASH scoring systems. Five patients died and four were lost to follow-up. Eleven patients had 2-part, eleven 3-part and eighteen 4-part fractures. Mean follow-up time was 21.7 months (range: 6-44 months). Radiological union was achieved within 8 weeks in 40/41 fractures; complications were noted in four cases. Better results were achieved in younger than in older patients, and in male than in female patients. The number of fracture fragments did not appear to affect the results, but associated dislocation of the humeral head was a pejorative factor. Our study has shown that the PHILOS plate is a reliable implant. A direct correlation was observed between Oxford shoulder and DASH scores.