Synovial chondromatosis is an uncommon disorder characterized by metaplastic formation of multiple cartilaginous and osteocartilaginous nodules within connective tissue of the synovial membrane of joints. Osteochondroma is a benign lesion of osseous and cartilagenous origin. It is frequently found in the general skeleton, but is rare in the mandibular condyle. We experienced 2 patients with abnormal appearance of temporomandibular joint. Histologic diagnoses were not obtained, because surgery was unwarranted in view of the lack of symptoms and the benign differential diagnosis. We describes 2 cases that show the characteristics of both disease simultaneously.