Osteochondroma is a benign tumor that is frequently developed in axial skeleton but rare in TMJ. 61-year old female patient visited local dental clinic with left TMJ crepitus on chewing, trismus and hearing discomforts. She was referred with a tentative diagnosis of TMD. We performed clinical and radiographic examination and could observe large radiopaque lesion at left TMJ. Excisional operation was performed. It was diagnosed finally with a osteochondroma.