Temporomandibular disorder (TMD) usually has non-specific signs and symptoms. The patient generally can only feel the pain, and thus complains about the stomatognathic problems without knowing the cause and the source. When the patient's chief complaint is pain, it is important to identify the source of the problem in order to provide appropriate treatment. Applied treatments for TMD can vary enormously. A female patient, age 35, came to the prosthodontic clinic with the chief complaints of pain in the right joint and limitation in mouth opening for past 7 years. In the last 2 weeks, the complaints worsened. With light pressure she could still open her mouth wider but showing deviations. She also complained about headache, tension in the forehead regionm and muscle pain in the upper back body. The patient also reported that she has been chewing only on the right side for more than 20 years. Lateral transcranial x-ray showed that there were no visible structural or positional disorders. Thus, jaw exercise was decided as the initial therapy for the patient. Within one week, all complaints disappeared. It was concluded that jaw exercise was a very useful form of treatment for TMD provided that the correct diagnosis is established.