Objective: This article presents an overview of the Personality Beliefs Questionnaire (PBQ)—a 126-item self-report measure of beliefs associated with 10 personality disorders. Design: It consolidates the literature on the PBQ over the last 20 years to provide a summary of the psychometric status, revisions and applications of the PBQ scales. Results: The PBQ scales are psychometrically reliable (α = 77–94, test-retest stability r=.57–.93) and discriminate between individuals with and without a specific personality disorder. Two revisions have been made to the measure: A 14-item subscale measuring beliefs central to borderline personality disorder has been identified, and a short form version of the PBQ has been validated. The PBQ has been used to measure cognitive mechanisms of treatment outcomes, and has been found to be sensitive to changes in beliefs. Conclusions: Given the proposed shift in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) to a dimensional conceptualization of psychological components of personality dysfunction, the PBQ is likely to remain relevant and useful for identifying such components in individuals with personality disorders. © 2011 Wiley Periodicals, Inc. J Clin Psychol: In Session 68:1–13, 2012.