One hundred sixty-two adolescents being seen for sick or well visits at two suburban private pediatric practices completed an anonymous, written questionnaire about drug habits. The respondents' ages ranged from 14 to 17 years; all were white and from middle-class or upper-middle-class families. The adolescents reported high self-esteem, good general health, and few psychologic problems. The majority of respondents stated that they and their good friends never used drugs. Seven adolescents (4%), however, reported having used marijuana during the previous week, and 13 (8%) during the previous month. When asked about the frequency of marijuana use by their good friends, 13 respondents (8%) said their friends had smoked marijuana 51 to 100 times, and another ten (6%) replied 21 to 50 times. The most frequently cited source of drugs was another student at school, whereas places drugs were commonly used included parties, rock concerts, and friends' houses. Even among a population of middle-class adolescents having follow-up in a suburban pediatric practice, use of marijuana and other drugs may constitute a serious health and psychologic problem. Physicians caring for adolescents must be aware of patterns of drug availability and use in their community, and should be prepared to recognize and remediate drug-related problems occurring in their patients.