Not much drug use was reported at school for any of the three groups, but reservation Indian youth were most likely to use drugs at school, followed by nonreservation Indian youth and non-Indian youth. Among all three groups alcohol and drugs were used most often at weekend parties and at night with friends. Reservation youth were twice as likely as the other groups to have used alcohol while driving, and they were three times more likely to have used drugs while driving. Drugs are used in the context of activities with friends, and heavy drug users are more likely to have friends who use drugs and encourage drug use. They are less likely to have friends who would attempt to stop them from using drugs. Youth who did not use drugs had some friends who used marijuana, but they were much more likely to have friends who would try to stop them from using drugs. The samples consisted of three groups of students, all of whom were surveyed in 1988-90. All three groups were administered the American Drug and Alcohol Survey under similar classroom conditions. The reservation Indian sample consisted of the 7th-12th grade students who lived on reservations. The Anglo and nonreservation Indian groups were part of a separate survey project conducted in junior and senior high schools across the United States. 5 tables and 2 references