In our study, we investigated the predictive value of illness beliefs as measured by the revised illness perception questionnaire (IPQ-R) in the context of other clinical predictors in patients with chronic orofacial pain over a 6-month follow-up period. Consecutive patients (152) referred to the interdisciplinary orofacial pain service at the Centre for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zurich received questionnaires to assess pain and pain-related disability, anxiety, depression as well as physical and mental quality of life at three time points: prior to treatment, 3 and 6 months after beginning of treatment. Results: significant improvement was found over time for all outcome measures except mental quality of life. Results of the regression analysis indicated that believing pain could have serious consequences on one's life (IPQ subscale consequences) is one of the most important predictors for treatment outcome. The belief in low personal control and in a chronic timeline is also shown to be predictive for outcome, though explaining a smaller proportion of variance. These results provided evidence that beliefs about pain are important predictors for treatment outcome even when controlled for pain and mood. They therefore need to be considered in the management of patients with chronic orofacial pain. Assessing patients’ illness beliefs can provide essential information on these important psychological determinants of adjustment to chronic pain and may be specific targets for individualised treatment approaches.