This paper reviews the behavioral-relaxation treatments of myofascial pain-dysfunction syndrome. The evidence indicates that this pain (located around the oral cavity) is due to muscle hyperactivity, most commonly of the lateral pterygoids. Research concerning relaxation techniques (i.e. progressive muscle relaxation and electromyographic feedback) has indicated the following: (a) in analogue research, normal healthy controls can learn to relax their muscles of mastication profoundly even during stress, and (b) in case reports, relaxation treatments are helpful clinical interventions, especially for pain patients who are not depressed, and who have not had the pain for more than a few years. Well controlled research is the next, essential step.