BACKGROUND: The purpose of this study was to figure out the prevalence of smoking, alcohol and other drug abuse and the relationships among them. METHODS: In July 1996, a total of 4,438 school adolescents randomly sampled from 6 schools(2 middle schools, 2 general high schools, 2 vocational high schools) in Seoul were assessed with a self-completing questionnaire pertaining to smoking, alcohol and other drug (sedatives, stimulants, inhalants) use. RESULTS: The current smoking rate of the study subjects in the study was 17.1%(male : 27.5%, female : 8.3%) and the current alcohol drinking rate was 29.4%(male: 34.0%, female : 25.4%). The experience rate of sedatives and stimulants was 4.0%(male : 4.7%, female 4.4%) and 12.1%(male : 7.0%, female : 16.6%), respectively. The experience rate of glue, butane gas and other volatile solvents was 1.3%(male : 2.5%, female : 0.4%), 0.8%(male : 2.0%, female : 0.2%) and 1.0%(male : 1.4%, female 0.6%), respectively. Current alcohol drinking as we71 as smoking was increased with age, higher in males than females, higher in vocational high school students than general high school students. The experience rate of stimulants was higher in females than males but the experience rate of inhalants(glue, butane gas, organic solvents) was higher in males than females. The younger the age of the study subject, the earlier the starting age of smoking and alcohol drinking. Smoking, alcohol and other drug use status was highly associated with one another. CONCLUSIONS: The most commonly used drugs by the study subjects were alcohol, cigarettes, stimulants, sedatives and inhalants in this order. Higher experience rate was seen in vocational high school students than general high school students.