The AIM of the study from which the empirical data were obtained for this thesis, was the collection of basic demographic information and selected health related data from a group of adolescents at high-school in Cape Town. 1.2 The OBJECTIVES were Description of the demographic features of the pupils in Standards 8, 9 and 10 at a specific co-educational high school in Cape Town; Determination of the prevalence of smoking, and the attitudes to, and knowledge of the health risks of smoking; Determination of the prevalence of alcohol use, and the attitudes to, and knowledge of the health risks of consuming alcohol; Determination of the prevalence of habit-forming drug use, and the attitudes to, and knowledge of the health risks of using drugs; Determination of the sexual experience of the pupils, attitudes to and knowledge of the health risks of sexual activity, and knowledge of contraception and venereal disease; Examination of whether the above habits correlated within individuals i.e. whether those who smoked were more likely to use drugs or be sexually active, and vice versa.