Isolated avulsion of the lesser tuberosity of the humerus is a rare injury. The mechanism of injury is the avulsion of the lesser tuberosity from forced contractions of the subscapularis muscle when the arm is forced into an externally rotated position on shoulder abduction. Authors report a case for isolated avulsion of the lesser tuberosity of the humerus which was treated with open reduction and transosseous suture fixation, as well as a view of the literature.