Synovial chondromatosis is an uncommon disease of cartilaginous transformation of synovial membrane with formation of loose bodies within the joint space. A case involving the temporomandibular joint (TMJ) is presented. In the TMJ, this disorder occurs more often in females and is usually on the right side. Symptoms include preauricular swelling, pain, and tenderness. Radiographs of the TMJ may be normal, but frequently show multiple, partially calcified loose bodies within the joint. Treatment consists of removal of the loose bodies together with all affected synovium. If the meniscus is excised, reconstruction with a Silastic prosthesis is recommended.