Posterior dislocation of the shoulder may be missed or neglected at initial presentation especially in developing countries. We present a case of 40-year-old Indian man who had 3-month missed posterior dislocation of the right shoulder along with malunited fracture of the anatomical neck of the humerus. Open reduction and stabilization with modified McLaughlin procedure was performed. Rotational osteotomy of proximal humerus had to be performed as supplementary procedure to keep the humeral head stable in glenoid cavity during functional range of movements. The patient had excellent result of the shoulder at 3 years follow-up.