The bachelor thesis deals with adolescent risky behaviour in connection with their sports activity. The theoretical part explains the concept of adolescence and risky behaviour. It also deals with the causes and manifestations of such behaviour. Moreover, this section contains a review of the history of sport and view of its current status in the context of the youth of today. In the empirical part the results of the questionnaire are presented and the lifestyle of athletic and non-athletic adolescents is evaluated. One of the important findings of the thesis was the lack of preventive programmes on risky behaviour in schools.