Two large data sets of 9th and 11th grade California students were used in the study. The statewide survey sampled 2,288 9th grade and 2,653 11th grade students from 44 secondary schools. Student responses were anonymous and provided data on demographic and psychosocial variables. Over 70 percent of academically successful students reported some type of drug use. Students were further divided according to their involvement with drugs (abstainers, conventional users, and high-risk users). It was found that about 72 percent of all high-academically involved 11th grade students engaged in drug use. Academically successful high-risk users were mostly female and reported the lowest percentage of intact families of any group in the statewide sample. Data analysis indicated that the negative association between drug use and academic achievement may be counterbalanced by such mediating factors as high educational aspiration, parent educational level, and emotional stability. 27 references and 4 tables