Locked posterior shoulder dislocations are an uncommon but difficult problem for the orthopaedic clinician. Furthermore, they are often missed on initial presentation, resulting in significant delays in treatment. Traditional treatment has involved formal open reduction, most commonly from an anterior approach, followed by transfer of the lesser tuberosity or subscapularis tendon into the anterior humeral head defect. We present the case of a patient with locked posterior shoulder dislocation, who was treated with arthroscopically assisted reduction followed by arthroscopic posterior stabilization. Use of this technique allows the surgeon to reduce the dislocation without performing an open arthrotomy, thereby decreasing the patient's overall morbidity. Furthermore, an arthroscopic technique used for stabilization allows visualization of the entire glenohumeral joint and enables the surgeon to directly address posterior disease, rather than compensating for the defect with an anteriorly based transfer.