This article aims to present the characteristics of sex education in selected European countries. Particular attention should be paid to the need for compulsory and diligently conducted sexual education of young people as a preventive measure and a factor providing objective scientific truth. Normative systems and set of beliefs often create social taboos about sexuality. Based on the analysis of scientific sources published in Polish, French and English, this article also shows the essence of sex education in schools, as a way for young people to make the right choices, reduce the occurrence of risky behaviors and protect against and prevent sexually transmitted diseases, unplanned pregnancy and sexual violence. Acquiring true and consistent with the current state of knowledge information on the human sexual sphere should be carried out throughout life. Conducting professional sex education classes at school would be an opportunity for all students to have equal access to information on this subject. Both for those who talk to their parents and those for whom it is a taboo. The presented effects of the lack of sexual education in schools show that its reliable and professional implementation is a means of providing help to young people and their families. However, in order to change the approach of parents and students to attending classes in this subject, it is necessary to improve the quality of teaching in this subject and to make some changes to the curriculum.