Sexually transmitted diseases (STDs) have been a significant global health problem for a long time. Approximately 300-350 million people in the world get infected by sexually transmitted diseases every year; and two thirds of them are under the age of 25. The viral sexually transmitted diseases discussed in this thesis are human papillomavirus (HPV), human immunodeficiency virus (HIV), hepatitis B virus and herpes simplex virus. The rate of infection spread depends on the average number of people infected, which depends on the effectiveness of transmission, on the type of sexual intercourse, on the number of sexual partners, and on the average length of the infection period. The biggest difficulties in coping with sexually transmitted diseases are complications and the consequences of infection. The safe sex goal is the protection against STDs and protection against unplanned and unwanted pregnancies. Nonetheless, the unique contraception type that could fulfil both purposes is still unavailable. In the conducted questionnaire survey, the knowledge of nursing students on viral sexually transmitted diseases and responsible sexual behaviour was analysed. The research consisting of 33 questions questionnaire was conducted online, Google Forms were used as a survey tool; and the study was conducted from March 5 to March 12, 2019. The research was intended to prove that STDs are one of the most important public health problems of today that have a significant impact on the quality of life of the population and aimed to point out the importance of on-going education and prevention of the transmission of STDs – both of students themselves and other people with whom the nursing students will be in contact during their working life. In the research, 439 (84.4%) of 520 participants are women. Most participants, 334 of them (64.2%) are between the age of 19 and 24. The most of participants are the 3rd year of nursing study, i.e. 197 (37.9%). We can conclude that the most common age of getting into the first sex experience is between 15 and 17 (48.8%), and the most commonly used contraceptives are condoms (43.5%). Significant number of students, more specifically 198 (38.1%) of them, believe that the HIV is transmitted via fecal-oral route and 12 (2.3%) that HIV is transmitted by air. As many as 210 (40.4%) of students do not know the important details of the HIV transmission pathway, nor the fact that there are no effective treatment methods for HIV yet, which is unknown by 228 (43.8%) participants. Therefore, it is pivotal to improve the knowledge of nursing students in order to acquire at least basic knowledge of viral sexually transmitted causes and diseases, especially given that this research has shown the lack of knowledge of the basic features of sexually transmitted diseases.