Synovial chondromatos is (SC) is an uncommon disorder defined as reactive cartilaginous proliferation, characterised by synovial metaplasia (Yu, et al., 2004). With intra-articular proliferation of cartilaginous nodules originating from the synovial membrane. It mainly affects large joints such as knee, hip, shoulder, and elbow. Its manifestation in the Temporomandibular joint (TMJ), is a rare finding, occurring predominantly in females. CT, MRI and arthroscopy facilitate the clinical diagnosis of SC, but pathological analysis is mandatory to confirm the disease (Martín-Granizo et al., 2005). This paper reports a case of a 35 years old woman who presented with a long-standing history (1 year) of pain in right TMJ. There were no limitations to jaw opening. Initial clinical and Radiological picture done outside our hospital suggested a picture of osteosarcoma, for which she received treatment. Histological and follow-up features of this lesion diagnosed it as SC of the TMJ.