The period of adolescence is the most risky stage when it comes to the beginning of the consumption of illegal psychoactive substances, and the goal of this research is the examination of social and individual factors that contribute to this phenomenon. Specifically, this study has aimed to determine the contribution of personal characteristics, affective states and characteristics of social environment to the use of illegal psychoactive substances in adolescence. The sample consisted of 629 adolescents, high school students. Multivariate analysis of covariance confirmed the existence of a significant relation between the studied social and individual factors with the use of illegal psychoactive substances in young people. Social environment factors, namely the use of illegal psychoactive substances by peers, proved to be the most important for this behavior in adolescents. In addition, significant factors of using illegal substances in adolescence have proved to be personality traits extraversion, openness, agreeableness, conscientiousness, dysphoria, stressful experiences in a social context - the total number of stressors, family and school stressors, and the availability of illegal psychoactive substance in the social environment of adolescents. These results can be applied to design appropriate prevention programs.