Diploma thesis „Impact of advertising on selected target group“ deals with the concept of advertising in its theoretical part, where it defines goals, substance, ethics and psychological aspects of advertising. It also defines the impact of advertising on individuals as well as on society. The next part deals with the developmental psychology of children, where it defines the period of adolescence. A separate chapter is devoted to children's advertising and marketing that is child-oriented. The practical part is devoted into research, which was attended by students of the second grade of a primary school in Banská Bystrica. The main goal of the research was to find the answer to what extent children affect children. The set hypotheses compared the different impact of advertising in individual years.