Unlike previous epidemiological studies, which used questionnaires to gauge responses, the author used unobtrusive methods. With three assistants, the author interviewed and observed 320 partygoers (200 males and 120 females) aged between 14 and 25 years, over a period of six months (January to July 1985) at nightclubs and house parties. The observed pattern of use was not different from that found in previous research. Adolescents tended to use the following drugs, in order of predominance: alcohol, cigarettes, stimulants, cannabis (Indian hemp), and sedative-hypnotics. Polydrug use, especially of alcohol, stimulants, and cigarettes, is common. The use of hard drugs (narcotics) was not reported in this study. The implications of the findings can be appreciated only against the background of the known sequelae (psychological, physical, socioeconomic) of psychoactive drug abuse. To curtail adolescent drug abuse, the following measures should be implemented: 1) new recreational facilities should be established and older ones improved, 2) existing drug laws should be strictly enforced, 3) drug abuse education should be included in primary and postprimary curricula, and 4) adolescents should be encouraged to participate in youth clubs and organizations. 19 references. (Author abstract modified)