BACKGROUND Therapeutic management of proximal humerus fractures is still controversial. There are several ways of proceeding in these cases, ranging from conservative treatment to shoulder joint arthroplasty. Open surgical reduction and stabilization with a locking compression plate is currently the most widely used method of treatment, especially in younger patients. The purpose of this study is to analyze the results of surgical treatment of fractures of the proximal humerus using locking compression plates. METHODS The study included 69 patients, 57 of them reported for the follow-up (82.6% of respondents). Clinical and radiological evaluation was performed at 6 weeks and 6 months following the surgery. Functional outcome was assessed using the Constant score. We also evaluated shoulder flexion active range of motion. Bone union and common complications were evaluated on the basis of radiographs--humeral head necrosis and the evidence of loosening of the bone-binding material. RESULTS The mean Constant score was 68.9 points and 75.94% relative to the opposite limb (relative mean score). No bone healing was observed in 7% (4 of 57) patients. There was a total of 21% (12 of 57) cases of humeral head necrosis. These changes varied in nature, location and severity. In 2 cases, reoperation was required due to loosening of the bone-binding material. Shoulder flexion active range of motion averaged 132 degrees and was lower in cases of 4-part fractures. CONCLUSIONS Surgical treatment of stable 3-part fractures of the proximal humerus using locking compression plate should be the treatment of choice in younger patients. Given the poor results, the choice of treatment involving 4-part fractures should be individually tailored.