A study was conducted on a representative sample of high school students in Hautes-Pyrénées, to measure their consumption of toxics (tobacco, alcohol, psychotropic and illicit drugs) and to explore the role of selected explanatory factors. Consumption levels were high, particularly for tobacco: 45% were smoker and 4% smoked more than 15 cigarettes each day. Less than 5% were alcohol daily consumers. Technical school students are a high risk population when they are 16 years old or less. Evening out represents a risk indicator: use of toxics is more frequent for students having twice evenings out each month or more. Prevention should be global, including the adolescents concerned and adults.