PURPOSE OF THE STUDY Unsatisfactory functional results following hemiarthroplasty (HA) are seen in the treatment of 3- and 4-part proximal humeral fractures due to tuberosity healing problems and rotator cuff tears. Reverse shoulder arthroplasty (RSA) has been popular for improving functional outcomes. This study compares the results of HA and RSA in the treatment of comminuted proximal humeral fractures in the elderly. MATERIAL AND METHODS Patients over 60 years of age with three- or four-part proximal humeral fractures were included in the study. Twenty-five patients were treated with HA and 33 patients with RSA. The patients were evaluated with/using the American Shoulder and Elbow Surgeons (ASES) and Constant scores, active and passive ranges of motions of the shoulders and muscle strength measurements of HA and RSA patients were compared. RESULTS The mean age of the patients was 66 (60-85) years in the HA group and 73 (60-83) years in the RSA group. The mean ASES and Constant scores were 44.6 and 70 (p=0.06), 24 and 49 (p=0.022), respectively. The mean active abduction was measured as 50° and 90° (p=0.001), flexions as 70° and 120° (p=0.02), and external rotation as 30° and 50° (p=0.210), respectively. CONCLUSIONS In the treatment of three- or four-part proximal humeral fractures of the elderly, RSA gives significantly better functional results compared to HA. Key words: proximal humeral fractures, hemiarthroplasty, reverse shoulder arthroplasty.