Modeling of a specific behavior by peers and adults is an important influence on an adolescent's choice to engage in that behavior. This study examined the impact of perceived peer and adult substance use on reported self-use within groups of black, Hispanic, Asian, and white teenagers. Effects were studied for four types of drugs: beer/wine, hard liquor, marijuana, and pills. In general, Asians and blacks reported the least self-use, whites reported the most peer models, and blacks reported the most adult models. Differential patterns of increase in use and perceived use by grade level were found across the four ethnic groups. Overall, perceived peer use of beer/wine, liquor, and marijuana was associated more with self-use than was perceived adult use. For pill use, only whites reported significantly greater influence of peers over adults on their self-use. For all substances, blacks reported the least impact of peer use on self-use relative to the three other groups. In regard to the impact of adult use on self-use, blacks and Hispanics reported the lowest for beer or wine; blacks and Asians reported the lowest for marijuana; and whites reported the highest for pills. These results are discussed in the context of differential vulnerability to modeling and vicarious learning.