Data came from anonymous self-report drug use surveys administered to a nationwide sample of 113,289 students ages 10-19. The sample was a convenience sample, because the sites surveyed consisted of schools that called to order a report on drug use statistics for their students based on survey results. Most of the schools were located in the midwestern and northeastern regions of the country. Eighty- seven percent of enrolled students at the participating schools took part. Findings revealed that a youth who used specific drugs in the last 30 days almost invariably has friends who also use those same drugs, but is considerably less likely to have friends who use other drugs or no drugs. In addition, friends' drug use is strongly associated with the adolescents use of marijuana, uppers, cocaine, downers, and PCP across five distinct drug use styles. Table and 43 references (Author abstract modified)