||This bachelor thesis focuses on indicating the factors, which influence the participation in adolescent substance use. Possibly important factors are identified based on the previous researches dealing with the same topic. The effect of these factors is then tested with the empirical model. This thesis deals with a dataset from the European School Survey Project on Alcohol and Other Drugs done at the Czech high schools among freshmen and juniors. Since the results in dependence on sex and class year are expected to be different, the regression is run separately. The most significant factors are for all cases: the smoking experience, the age of the first intoxication, and the share of friends who already consume alcohol.