Primary synovial chondromatosis of the shoulder is a rare condition. We present the case of a 24-year-old man with a 6-month history of right shoulder pain and decreased range of motion. Computed tomography and magnetic resonance imaging findings led us to the diagnosis of synovial chondromatosis of the shoulder. Arthroscopy revealed loose bodies in the glenohumeral joint, the biceps tendon sheath, and the subscapularis recess. Active intrasynovial proliferation of the axillary pouch was noted. All loose bodies were removed arthroscopically, and partial synovectomy was performed. Histologic examination confirmed the diagnosis of primary synovial chondromatosis. We recommend arthroscopic treatment for synovial chondromatosis of the shoulder because of low morbidity and early functional return.