Although common, AC joint injuries and their treatments are not benign. The injury itself and both nonsurgical and surgical treatments may result in complications yielding persistent pain, deformity, or dysfunction. Sternoclavicular joint injuries are far less common and are typically the result of higher energy trauma. As such, the associated complications may be more serious. Familiarity with the potential complications of these injuries can help the treating physician to develop strategies to minimize their incidence and sequelae.