Objectives: Examine the knowledge of the students from the Health and Veterinary High School Dr. Andrija Štampar Vinkovci regarding sexually transmitted diseases as well as their ways of transmission. The specific objectives are to examine the age at which students engage in sexual relations, find out whether they were under the influence of alcohol before their last sexual encounter and find out where they are informed regarding sexually transmitted diseases. Study design: Cross-sectional research. Participants and methods: The research was conducted on 121 respondents in the Health and Veterinary High School Dr. Andrija Štampar Vinkovci. Adult students from the 4th and 5th years participated in the research, in the programs medical nurse/technician of general healthcare, physiotherapy technicians and veterinary technicians. The research was carried out using an anonymous online survey consisting of 29 questions, and participation in the research was voluntary. Results: Thirty-one male and ninety female respondents participated in the research. 49% of the respondents have had sexual relations until now. Seventy-four respondents stated that they have enough knowledge regarding sexually transmitted diseases. Every question about sexually transmitted diseases in the survey had a correct answer, and their total number is 14, and the median of correct answers in our sample is 10 correct answers. Conclusion: The students of the Health and Veterinary High School Dr. Andrija Štampar Vinkovci have a good knowledge of sexually transmitted diseases. The most common age of entering sexual relations is 18, and the most common type of protection used is a condom. Students most often find information regarding sexually transmitted diseases on the Internet. The females showed a significantly higher level of knowledge than the males, as well as the 5th year students compared to the 4th.