Congenital heart defects are abnormalities in development that can affect large blood vessels and the structures of the heart itself. Congenital heart defects and large blood vessel defects occur on average in 6 to 10 cases per 1000 newborns, respectively in an average of about 0.8% of live-born children. They are caused by genetic factors or teratogenic substances that act on the fetus at the time of embryonic development. According to hemodynamic features, congenital heart defects are divided into defects without shunt, defects with left-right shunt and defects with right-left shunt. They vary from simple to complex and have separate and different characteristics from each other. Advances in medicine and technology have enabled the early detection and adequate and timely treatment of congenital heart defects in children, which seeks to ensure a quality and undisturbed life for the child to old age. As part of this final thesis, a research was conducted with the aim of gaining insight into the knowledge of undergraduate nursing students about congenital heart defects. The research was conducted among 70 students of the undergraduate study of nursing at the Faculty of Health Studies in Rijeka in the form of an anonymous online questionnaire developed in Google forms. The data analysis obtained by the research showed that the students of the second year of nursing have the most knowledge about congenital heart defects, while the students of the first year have the least knowledge. In order for future bachelors of nursing to be able to plan and ensure adequate and quality health care, the expertise and knowledge they will acquire through education is important, and they will be able to further apply the acquired competencies in their daily work as members of the health team.