Abstract Objective This article analyzes the psychometric and structural properties of the Brief Symptoms Inventory 18 in a sample of patients with temporomandibular disorders (TMDs), given the convenience of a brief evaluation of distress in these patients. Methods Confirmatory factor analysis was carried out in a sample of 114 patients with TMDs. Two models were tested: the theoretical model with the original structure proposed—which considers three dimensions—and the empirical model obtained through the exploratory factor analysis initially carried out by Leonard R. Derogatis—which consists of the four-factor structure. Results Both models reached satisfactory indexes in confirmatory factor analysis. Empirical and theoretical reasons led us to prefer the original proposal of three dimensions: somatization, depression and anxiety, and general distress. Conclusion The Brief Symptoms Inventory 18 has been demonstrated to be a reliable and valid tool for the assessment of distress in patients with TMDs, with the advantage of its simplicity and ease of application.