Posterior shoulder dislocations can cause impaction of the anteromedial part of the humeral head: this is called a reverse Hill-Sachs lesion. Such defects may predispose to chronic instability of the shoulder and may require surgical intervention. However, to the best of our knowledge, these lesions have not been filled with the mozaicplasty technique using the patient’s own cartilage. A 24-year-old male patient was admitted to our hospital as a result of a seizure. Examination of the right shoulder revealed pain and restriction of motion in external rotation. Anteroposterior radiographs and computed tomography scans showed a locked posterior shoulder dislocation and fracture of the lesser tuberosity. Measurements presented a lesion including approximately 30% of the articular surface. Anteromedial cartilage defect was filled with autogenous osteochondral plugs harvested from both the knees. At the 2-year follow-up, the patient had no recurrent instability and supple range of motion of his shoulder. Treatment of reverse Hill-Sachs lesion varies depending on the percentage of articular surface involvement. In general, defects up to 40% of articular surface were treated with elevation of the cartilage, subscapularis shift, lesser tuberosity advancement, and filling defects with allografts. The described technique can be performed in young patients with unilateral small-sized or medium-sized defects while the anatomic reconstruction was performed. Computed tomography of the patient showed graft osseointegration to host bone and continuity of smooth articular surface.