This paper examines differences among three racial groups in exposure to three risk factors for drug use (availability of drugs, acceptability of drug use, and peer alcohol use), and the relationship of these factors to drug use initiation in a sample of preadolescent urban youths. Tobacco and alcohol initiation rates were highest among Whites, lower among Blacks, and lowest among Asian-Americans. Paralleling these differences, White youths reported the greatest access to marijuana, greatest parental tolerance of substance use, and greatest intentions to use drugs as adults. Blacks somewhat less, and Asian-Americans the least. No racial differences appear in the proportion who reported that their peers used alcohol. Marijuana availability and peer use predicted substance initiation for all three racial groups. However, intentions to use substances as an adult and perceived parental tolerance of substance use predicted drug use only for White and Asian-American youths, while the expectation of punishment for drug use predicted lower drug use only among Black youths. Implications for prevention are discussed.