The construct of "pain behaviors" as observable and measurable manifestations of pain occupies a central role in Fordyce's operant model of pain. The present study was designed to evaluate the multidimensional nature of the construct and to explore the psychometric properties of a newly developed self-report instrument called the Pain Behavior Check List (PBCL). Subjects were 126 chronic pain patients who completed an initial version of the PBCL and other standardized questionnaires as part of their evaluation by the West Haven VAMC. Factor analysis identified four factors labeled Distorted Ambulation, Affective Distress, Facial/Audible Expressions, and Seeking Help. Substantial reliability and stability estimates for the total PBCL and the subscales support the potential clinical and theoretical utility of the instrument.