OBJECTIVE: Recent policy has focused on documenting and reducing ethnic disparities in availability and quality of health care. The authors examined differences by ethnic status in unmet need for alcoholism, drug abuse, and mental health treatment. METHOD: Data were from a follow-up survey of adult respondents to a 1996-1997 national survey. Non-Hispanic whites, African Americans, and Hispanics were compared in access to alcoholism and drug abuse treatment and mental health care (primary or specialty), unmet need for care, satisfaction with care, and use of active treatment for alcoholism, drug abuse, and mental health problems in the prior 12 months. RESULTS: A total of 31.9% of whites, 28.1% of African Americans, and 30.1% of Hispanics had some alcoholism, drug abuse, and mental health care, mostly in primary care. Among those with perceived need, compared to whites, African Americans were more likely to have no access to alcoholism, drug abuse, or mental health care (25.4% versus 12.5%), and Hispanics were more likely to have less care than needed or delayed care (22.7% versus 10.7%). Among those with need, whites were more likely than Hispanics or African Americans to be receiving active alcoholism, drug abuse, or mental health treatment (37.6% versus 22.4%-25.0%). CONCLUSIONS: The authors document greater unmet need for alcoholism and drug abuse treatment and mental health care among African American and Hispanics relative to whites. New policies are needed to improve access to and quality of alcoholism, drug abuse, and mental health treatment across diverse populations.