A prospective study of 60 patients with the temporomandibular pain and dysfunction syndrome (TMPDS) was done using the General Health Questionnaire, the Crown-Crisp Experiential Index, and the Parental Bonding Instrument. Three months after an initial visit 59 patients were reassessed: 18 patients were completely better or improved a lot, 27 were improved a little, and 14 were the same or worse. Patients' outcomes were not related to the severity or duration of symptoms at the initial presentation. Thirty-five percent of the patients had not received any therapy in the 3-month interval. The outcomes of these patients were not different from the outcomes of patients who had received treatment. A significant relationship was found between initial psychological test scores and outcome (multivariate F = 3.80, P less than 0.05). This relationship was curvilinear: the group with the worst outcomes scored highest, that with the best outcomes scored in the middle, and that with intermediate outcomes scored lowest. These results imply that mild psychological distress may facilitate a successful outcome, whereas either excessive psychological disturbance or minimal psychological complaint is associated with poor results.