To reduce complications and increase fixation after the internal fixation of proximal humeral fractures, interlocking intramedullary nailing and tension-band and locking sutures were used simultaneously, and their results are reviewed. Twenty-six consecutive patients who underwent open intramedullary nailing with tension-band and locking sutures for proximal humeral fractures were selected. The mean follow-up period was 39 months. With regard to the functional evaluation, the mean Neer score was 90 points and the mean American Shoulder and Elbow Surgeons score was 85. When patients were divided into those aged less than 65 years and those aged 65 years or greater and into those with 2-part fractures and those with 3-part fractures, postoperative pain, the American Shoulder and Elbow Surgeons score, and the Neer score showed no difference between the 2 groups. Open intramedullary nailing accompanied by tension-band and locking sutures for proximal humeral fractures shows sufficient fixation in older patients, and therefore, good postoperative shoulder function can be expected.