Introduction: Sexuality is one of the basic life needs. A positive experience of one's first sexual intercourse is reflected in self-esteem; individuals with a positive experience of their first sexual intercourse have more regular sexual intercourse and are more satisfied with their sexuality. Young people must be given the right information at the right time, by experts and in a way that is adapted to them. That way, they can enter their first sexual relationship ready, thus increasing their chances of a positive experience. Purpose: The purpose of the diploma thesis is to investigate changes to the age limit for first sexual intercourse, the degree of awareness about and the use of contraception, and to determine the sources of information about sexuality in Generations Y and Z. Methods: In the theoretical part, we used a descriptive research method with a literature review in the Slovenian and English language. The literature used in our thesis was searched in the databases Medline, Science Direct, Cinahl; with the Pubmed search engine; on the online portals Google Scholar and DiKul; in the physical form of scientific articles and books from the National University Library of Ljubljana. In the empirical part of the thesis, a quantitative method was used with the help of an online survey questionnaire. The target population were individuals born between 1981 and 2012. Volunteers filled out an anonymous questionnaire containing 13 questions and 4 sub-questions. The survey was created using the online survey tool EnKlikAnketa (1KA). It was shared on Facebook and via e-mails. After collecting the responses, basic descriptive statistics were performed. The survey took place from 18 April to 30 April 2022. Results: A total of 330 questionnaires were completed. Of these, 72% of respondents were women and 28% were men; 44% were Generation Y, and 56% were Generation Z. The survey showed that the average age at the first sexual intercourse in Generation Y was 16.45, or 17.12 for Generation Z. The most common reason for the first intercourse is falling in love. Most young people received information about sexual and reproductive health from the media, books, newspapers, the Internet and pornographic sites, followed by school and peers. 80% of young people used contraception during their first sexual intercourse, which was more common for representatives of Generation Y than Generation Z, and they most often used a condom. Discussion and conclusion: The results of our research are comparable to the results of foreign research, except for the higher age at the first sexual intercourse for Generation Z. According to the source of information of the research participants, there is an obvious need for professional and systematic general sex education. Depending on the particularities of each generation, it is necessary to use different techniques for imparting knowledge.