Introduction: : Blood is often an irreplaceable medicine and we are all potential recipients of blood every day. Human being is the only source of blood and a potential voluntary donor. The lack of donors is a significant problem at the global level. Adequate blood supplies are crucial for the success of various medical interventions and the preservation of human life. Distorted attitudes and insufficient knowledge about donating blood can influence a person to decide not to donate blood. Objective: The objective of this paper is to examine the attitudes and knowledge of full-time and part-time undergraduate and graduate students of history, sociology, communicology, nursing, psychology and medicine about blood donation at the Catholic University of Croatia. Methods: An observational cross-sectional study was conducted. The research was conducted through an anonymous online survey that was adapted to the needs of this thesis. The first part of the survey contains sociodemographic questions, while the second and third parts examine the attitudes and knowledge of students about donating blood. The questionnaire is CADS-19, which was translated into Croatian according to the current rules for translation and adaptation. The research was conducted in March and April 2024. Results: All full-time and part-time undergraduate and graduate students of the Catholic University of Croatia were invited to participate in the research. A total of 314 students responded to the invitation. Almost all respondents (95,2 %) expressed their agreement with the statement about the need to donate blood, accordingly, the majority (80,6 %) are of the opinion that they will donate it in the future. The research participants demonstrated their knowledge about donating blood with more than 50 % correct answers in the knowledge test questionnaire. Conclusion: Adequate knowledge and positive attitudes towards blood donation are crucial in a person's decision to donate. Although students are sufficiently informed, according to the collected data, there are deficiencies. Educational campaigns are essential for creating an informed and engaged community. Additionally, raising awareness and developing positive attitudes among young people is of critical importance for establishing a stable base of donors and ensuring an adequate supply of blood in the healthcare system.