The study found significant similarities and differences among these ethnic groups in their distribution and exposure to the psychosocial risk and protective influences for drug use. The findings show that each of the protective and risk influences were consistent over time in the models of drug use for American-born Latino boys, foreign-born Latino boys, and White-American boys. This provides support for the use of these predictive models among these groups in future research intended to determine risk and prevention factors for drug use. There were also significant differences in relationships among key explanatory influences across American-born and foreign-born Latinos and White-Americans. These differences suggest it is useful to examine separate models in analyzing drug-use patterns across these ethnic groups. The proposed model did not accurately reflect the unique experiences and issues for African-American boys; for example, African-American boys tended to engage in drug use at a much later age compared to the other three groups. The influences and experiences of African-American boys are apparently significantly different from the other three ethnic groups at the developmental period examined. This finding argues for a more precise model for African-American boys that describe their specific progression into drug use and the unique risks and buffers that influence their decisions to use drugs. 2 tables, 4 figures, and 48 references