Primary and secondary prevention, which are in the domain of public health, are the first line of defense, and medical workers, especially nurses, are the ones to whom the public turns the most for opinions and advice regarding malignant diseases. Research goals: The main goal of the research was to collect data on the attitudes of nurses about the importance of the existence of national programs for the prevention of malignant diseases. In addition, their opinion on the duties of educating the population on the prevention of malignant diseases on their part, the possibilities of preventing death from malignant diseases and their personal response to responding to screening tests for certain malignant diseases was also investigated. Respondents and methods: Respondents were nurse from the Republic of Croatia, a total of 675 of them. They were divided on the basis of gender, age, professional qualification, years of experience and the level of healthcare in the healthcare institutions where they work. The data were obtained through a questionnaire that was filled out anonymously and were exclusively used for the purpose of research in this paper and accompanying scientific articles. Results: The attitudes of nurses about the importance of national programs for the prevention of malignant diseases are largely positive. 91% of respondents believe that national programs are the most important or extremely important in the prevention of malignant changes. 623 (92.3 %) respondents answered the question, do they think that health workers are obliged to educate the environment about the importance of preventing malignant diseases. 503 (74.5%) respondents agree that mortality from malignant diseases is preventive. Also, 60% of the respondents believe that regular visits to the doctor for preventive examinations are crucial in early detection, while 81% of them would or have already responded to screening as part of the national prevention program. Conclusion: Nurses attitudes are largely positive towards primary prevention and response to screening tests. Greater involvement of bachelor's and master's degrees in nursing in the preparation and implementation of national preventive programs in the Republic of Croatia can mean greater success in response and early detection of malignant changes.