Utilization of general medical and mental health services by respondents in the Los Angeles Epidemiologic Catchment Area (ECA) site was compared with that in three ECA sites studied previously (New Haven, Conn, Baltimore, and St Louis). Within the Los Angeles sample, Mexican-American patterns of utilization were compared with those for non-Hispanic whites. Los Angeles respondents were less likely than those at other ECA sites to make ambulatory health care visits and to be hospitalized for physical or mental health reasons. Mexican Americans were less likely than non-Hispanic whites to report ambulatory health care but were as likely to have been hospitalized. Six percent of Los Angeles respondents reported a recent mental-health-care visit as compared with 6% to 7% of respondents at the other ECA sites. However, among respondents with Diagnostic Interview Schedule DSM-III disorders diagnosed within the six months prior to the interview, a lower proportion made a mental health visit in Los Angeles (14%) compared with the other sites (16% to 20%). Of those who made a mental-health-care visit, Los Angeles respondents with a recently diagnosed disorder were more likely than comparable respondents at the other ECA sites to visit a mental health specialist rather than a general medical care provider. Mexican Americans with a recently diagnosed mental disorder were only half as likely as non-Hispanic whites (11% vs 22%, respectively) to have made a mental health visit. However, when Mexican Americans with Diagnostic Interview Schedule/DSM-III did make a mental health visit, they were as likely as non-Hispanic whites to see a mental health specialist.