A recent national survey of high school seniors indicated that substance abuse is a significant problem among adolescents. Results indicate that 92 percent of those surveyed had tried alcohol, 19.5 percent reported daily cigarette smoking, 4.9 percent used marijuana daily, and 61 percent had tried an illegal drug at some time in their lives. The consequences of substance use; the need for school-based programs; and sociological, psychological, behavioral, and developmental factors associated with substance abuse in adolescents are discussed. Also discussed are two types of prevention programs which are effective according to evidence in the literature, i.e, social influence and broad-spectrum programs. Social influence programs have focused mainly on preventing cigarette smoking. Broad-spectrum programs, which address a range of coping and resistance skills, are found to be somewhat effective in preventing alcohol and drug abuse. 41 references.