Osteochondromas are one of the most common detected benign bone tumors. They are often seen on the metaphysis of the long bones as a single mass. Synovial chondromatosis is a rare benign arthropathy affecting diarthrodial joints. Extraarticular localization is even less common. In this paper a rare case of a synovial ostheochondromatosis of the biceps tendon sheath is reported.