The literature review focuses on parental and sibling drug use, positive parental attitudes toward drug use, family management problems, family involvement and attachment, family structure, and family socioeconomic status. As part of a longitudinal study of substance use initiation in Seattle, Washington, data were obtained from 919 fifth grade students; 46 percent of the students were white, 25 percent were black, and 21 percent were Asian American. An examination of ethnic differences on measures of family predictors found significant differences. Regression analysis of black, white, and Asian American youth demonstrated significant differences by ethnicity in family management practices, involvement in family activities, sibling deviance, parental disapproval of children's drinking, and family structure. Regression equations identified both unique and common predictors of substances initiated by the end of fifth grade. Implications of the study findings for identifying differences in rates of substance initiation are discussed. 57 references and 2 tables