Introduction. In recent years, there has been a growing global trend in the number of people with pathogens of sexually transmitted infections. There is a worldwide lack of data on the prevalence and incidence of sexually transmitted infections in the general population, especially among the high school students. Material and Methods. We conducted a cross sectional study on attitudes and knowledge of young people about sexually transmitted infections. The survey population included young people aged 14 to 20 years attending a high school in the city of Novi Sad. The data were collected through a questionnaire. Results. The percentage of students with signs and symptoms of sexually transmitted infections was higher among the students who did not use a condom during the last sexual intercourse compared to the students who used a condom. Conclusion. Young people engaging in risky sexual behavior showed better knowledge about sexually transmitted infections in comparison to young people who did not engage in risky sexual behavior.