It is a consummate fact that the youths occupy, during the adolescence most of the day in the school, being that many prominent behaviours for the health are initiated in this phase of the life. It is for that fundamental that the schools be health promoters spaces.Objectives : to know the age of initiation to the consumption of alcoholic beverages, tobacco and illicit drugs in this sample; to calculate the prevalence rate of these consumption; to identify priority areas to approach in the Health Education process.

This is a descriptive and cross-sectional study, that is going to identify behaviours of risk for the health of High School students of Douro Region. The sample is constituted by 466 students of seven schools. The data were collected through a questionnaire on line, of Janeiro to March of 2007, disposed in the site http://jovemsaudavel.com.sapo.pt, designed for the effect. In the data treatment we utilize the statistical descriptive and the qui-square test.

The ages average of initiation to the consumption of alcoholic beverages, tobacco and illicit drugs is 12,5, 12,3 and 13,6 years, whereas the prevalence's of these consumption are 38,9%, 16,9% and 6,0%, respectively. Highlights-itself the sporadic consumption of alcoholic beverages (28,4%), the abusive consumption of tobacco (9,4%) and of illicit drugs (1,8%). The boys swallow beverages and smoke with bigger frequency than the girls ((c2: p = 0,006 and 0,001). They had intercourse relations already 27,7% of the students of this sample, of the which 11,9% did not use protection.