Objective: To identify the knowledge and self-care actions taken by nursing undergraduate students of a Federal University of the South of Brazil, against Sexually Transmitted Infections.
Method: Exploratory qualitative study, conducted 40 interviews with undergraduate students at the beginning and end of the course. The analysis was thematic, resulting in three categories.
Results: Knowledge about the subject is a decisive factor for self-care, and the more knowledge, the greater the prevention. The dissemination of knowledge of students at the end of the course not only influences self-care but also health promotion in the social sphere.
Final considerations: Knowledge is important in self-care and caring for others. The dissemination of knowledge becomes evident according to the complexity of the course. Stable relationships may interfere with the use or disuse of condoms in sexual relationships, a misnomer present in today's society.