PURPOSE: The purpose of this study is to compare the results of using a locking compression plate and an unlocked plate for treating proximal humeral fractures. MATERIALS AND METHODS: This study was based on 20 patients who underwent plate fixation for proximal humeral fractures out of the 87 patients with proximal humeral fractures and who were admitted from 2003 to 2007 in our hospital. Of the 20 patients, 10 were treated with a locking compression plate and the other 10 were treated with an unlocked plate. Each group was evaluated according to the humeral neck shaft angle, the period until bony union, the complications and the Constant score. The humeral neck shaft angle was based on plain x-rays taken immediately after the operation and at 6 months postoperatively. The Constant score was evaluated on the last visit to our clinic. RESULTS: There was no significant statistical difference between the two groups in terms of the neck shaft angle, the period until bony union and the Constant score. Yet, there were three cases of screw migration in the unlocked plate group. CONCLUSION: There was no significant difference between the two groups in terms of the neck shaft angle, the period until bony union and the Constant score. The locking compression plate is considered to achieve more effective fixation for proximal humerus fractures because there were less complications such as screw migration.