The authors present the clinical characteristics, demographic features, and family history of a clinical sample of 44 patients who met DSM-III criteria for obsessive-compulsive disorder. Their findings are consistent with those of previous epidemiologic studies completed before the introduction of DSM-III with regard to phenomenology, course, and demographic characteristics. Most of the 44 patients had concomitant or lifetime histories of a major depressive disorder or another anxiety disorder. A number of first-degree relatives of these patients had probable obsessive-compulsive disorder or obsessive traits. The findings of this study should prove useful in further epidemiologic, biologic, and behavioral studies.