This paper examines the association between DSM-IV alcohol dependence, drug use and DSM-IV drug/abuse dependence in a sample of White (n = 256), Black (n = 263) and Mexican American (n = 212) men consecutively admitted to five alcohol treatment programs in a Northern California county. Results show that drug use is higher among Blacks and Mexican Americans than among Whites. About 35% of the Whites 43% of the Blacks and 35% of the Mexican Americans are both alcohol and drug dependent. Among alcohol dependent individuals, about 44% of the Whites, 72% of the blacks and 52% of the Mexican Americans report using at least one drug other than alcohol once a week or more in the 12 months previous to the interview. The drug most frequently used by Whites is marijuana, followed by cocaine and amphetamines. The drug most frequently used by Blacks and Mexican Americans is cocaine, followed by marijuana. Severity of drug dependence is inversely related to severity of alcohol dependence among Whites. Alcohol treatment programs for Whites, Blacks and Mexican Americans must offer assessment, treatment matching and relapse prevention that takes into consideration this high prevalence of drug use and dependence.