Background: To examine ethnic groups differences in (a) prevalence of depressive disorders and (b) health related quality of life in fee-for-service and managed care patients (n=21 504) seeking care in general medical settings. Methods: Data are from the Medical Outcomes Study, a multi-site observational study of outpatient practices. The study screened patients of clinicians (family practice, internal medicine, cardiology, diabetology and endocrinology) for four chronic medical conditions; depression, coronary heart disease, hypertension and diabetes. A brief eight-item depression screener followed by the Diagnostic Interview Schedule-Depression Section (DIS) for screener positives identified depressed patients (n=2195). The Short Form Health Survey (SF-36) assessed health-related quality of life. Patient self-report determined ethnicity. Results: Before adjusting for demographic factors, African-Americans and Hispanics had highest rates of depressive symptoms. Asian-Americans had the lowest. adjusting for demographics (particularly gender and income), we found few statistically significant differences in prevalence or severity of depression. However, among the depressed, Whites were the most, and African-Americans the least likely to report suicidal ideation (p<0.01), and Hispanics and Whites were more likely to have melancholia (p<0.01). African-Americans reported the poorest quality of life. Limitations: DSM III criteria (though few changes in DSM IV), and relatively small sample size of Asian-Americans compared to other groups. Conclusions: Gender and socioeconomic status are more significant factors than ethnicity in determining risk for depressive disorder. However, ethnic differences in symptom presentation, and health-related quality of life could have clinical and social consequences, and merit further study.