Introduction: Cardiovascular diseases are diseases of the heart and blood vessels and are one of the leading global causes of mortality and morbidity in the world, thus representing one of the biggest public health problems in the world. Aim: To determine the knowledge, attitudes and perception of the general adult population about cardiovascular diseases, their risk factors and how cardiovascular diseases affect the quality of life. Methods: The research was conducted on 393 respondents via an anonymous online form in Split-Dalmatia County. The questionnaire consists of a sociodemographic questionnaire and an ABCD questionnaire. The research was conducted from May 1, 2023 to May 17, 2023. Results: 2.28 times more women than men participated in the research. The average age of the respondents is 33 years. The average body weight of the subjects is 74 kg. The average level of knowledge of the respondents about cardiovascular diseases is 71.28%. The overall level of perception of heart/stroke is 16.91, which indicates a moderate level of perceived risk of heart/stroke among the respondents. The overall level of perceived benefit and intention to change is 2.97, which indicates a high level of perceived benefit and intention to change among respondents. The level of intention to eat healthy is 2.58 among respondents, which represents the average level of intention to eat healthy among respondents. Cronbach α of the validated ABCD risk questionnaire is 0.538, and the values for each factor are: knowledge (0.54), perceived risk of heart attack/stroke (0.84), perceived benefits and intentions to change (0.89) and intentions to healthy diet (0.72). Conclusion: The Croatian version of the ABCD - risk questionnaire has satisfactory measurement characteristics for the assessment of knowledge, attitudes and beliefs about cardiovascular diseases. Level of education is positively related to knowledge and attitudes about cardiovascular. There is a correlation between physical activity, eating habits, family disposition, stress and harmful behaviours in relation to cardiovascular diseases.