Tobacco, alcohol, and drug use are problems for American-Indian people. We reviewed these problems and the explanations for them and described a bicultural competence skills approach for preventing substance abuse with American-Indian adolescents. Data from a study of that approach suggest its efficacy with American-Indian youth. At posttest and a 6-month follow-up, AmericanIndian subjects who received preventive intervention based on bicultural competence skills concepts improved more than did American-Indian subjects in a no-intervention control condition on measures of substance-use knowledge, attitudes, and interactive skills, and on self-reported rates of tobacco, alcohol, and drug use. Our findings have implications for future substance-abuse prevention research with American-Indian people.Earlier, in this journal, LaFromboise and Rowe (1983) noted the value of skills training to increase bicultural competence among American-Indian people. According to LaFromboise and Rowe, bicultural competence is the capacity of "making one's desires or preferences known in an Indian or in a non-Indian setting" (p. 592). Bicultural competence skills seem appropriate for use in helping American-Indian young people combat substance abuse and its related problems. More than other Americans, Indian and Alaska-Native children and adults suffer from such substance-related problems as school failure, antisocial behavior, unemployment, criminal arrest, and increased morbidity and mortality (