The main objectives of this study were: to provide estimates of the prevalence of substance use among young people attending second-level schools in Cork City; and, to provide systematic data on the socio- psychological factors related to these behaviours and attitudes for this population. This interim report sought to address the first objective of the research project, viz., describing attitudes and behaviours. The following were the main findings of this part of the study: Over two-thirds (72%) of the sample had smoked a cigarette and 25% were regular smokers; Over three-quarters of the pupils (78%) had consumed a whole drink of an alcoholic beverage on at least one occasion, over half had felt "drunk" on at least one occasion and 51% could be classified as regular-occasional drinkers; One-fifth of the students had tried drugs other than tobacco and alcohol. The most popular illicit drugs were marijuana and inhalants such as glue, solvents or gas. 6% of pupils claimed to have a regular source of drugs.The data presented in this report suggest a number of conclusions. Firstly, a significantly large majority of the sample population had experimented with alcohol and tobacco, and a significant minority had used other substances, some legal and others illegal. A second conclusion suggests that a major need exists for a comprehensive and articulated set of primary preventative-educational programmes to combat such use and abuse.