Current economic constraints necessitate careful planning and evaluation of mental health services. Gender differences in need and use of outpatient mental health services are synthesized based on current epidemiological research. Although overall prevalence rates of mental disorder are similar, women use more outpatient mental health services than do men. This disparity exists largely within the primary care sector. The study of social roles and behavior may help explain these gender differences. Implications for planning and organizing outpatient mental health services are discussed.