Synovial chondromatosis is an uncommon disease of cartilage transformation of synovial membrane with formation of loose bodies within the joint space. The knee and elbow are the most commonly involved sites and involvement of temporomandibular joint is very rare. Symtoms include swelling, pain, stiffness of the jaw, and inability to close the jaw. A case involving the temporomandibular joint (TMJ) is presented. A 28-year-old women had experienced pain of the left TMJ area and limitation of mouth opening. Radiographs of the left TMJ revealed calcified mass surrounding over the mandibular condyle and under the glenoid fossa. Treatment consisted of removal of calcified mass, reshaping of affected condyle and reconstruction with a auricular cartilage. After surgery, the patient's range of motion improved although deviation to the affected side. Until present after surgery there have been no recurrence of symtoms. We think that findings of this patitent agree with those of synovial synchondrmatosis in many aspects.