This report is based on a study into the use of cigarettes, alcohol and other drugs by post-primary schoolchildren in Dublin. A survey was pf 5483 pupils in 154 randomly chosen schools in Dublin was carried out in the spring of 1970. Data were collected by means of structured questionnaire. A total of 126 respondents claimed to have taken drugs. Cannabis (53%) was the most common drug; 11 had taken LSD; and 9 had taken sedatives. The results of the survey reflect the pattern of drug use reported in a similar survey in an urban area of the England around the same time.