We report a study of sexual function in outpatient men with major depressive disorder (n = 42), compared with healthy control men (n = 37) and a clinic sample complaining of erectile dysfunction (n = 13). A principal-components factor analysis of the Brief Sexual Function Questionnaire confirmed differences in the clinical dimensions of sexual activity/performance, interest, satisfaction, and physiological competence. The four factors accounted for 72% of the variance in the analysis. Acceptable test-retest reliability, construct validity, and concurrent validity (with the Derogatis Sexual Function Inventory and a self-report behavioral log) were demonstrated. Parallel observations with findings from previous nocturnal penile tumescence studies in these same men are discussed.