The discussion emphasizes that substance abuse affects millions of Americans in all socioeconomic groups and geographic areas. Substance abuse causes illness, death, injuries, school problems, family breakup, an crime. It strains the health care system, as well as the education, social service, and criminal justice systems and places a large and unnecessary burden on the economy. Many trends are disturbing. Although overall consumption is down, frequent heavy use is relatively unchanged. Mortality related to drug abuse remains high and is increasing dramatically for drug- related AIDS deaths. Drug-related crime continues to grow. However, awareness of the health risk associated with substance abuse is increasing, and the public is growing more intolerant of abuse. Most communities have at least some prevention, intervention, and treatment activities, and these activities are increasing. Figures and list of suggested readings