INTRODUCTION: Cardiopulmonary resuscitation (CPR) is a combination of heart massage and artificial respiration, and is performed to restore heart and lung function to a person who has experienced cardiac or respiratory arrest. The aim of this work is to examine the knowledge and willingness of lay people in Croatia to provide first aid in case of cardiac arrest. MATERIALS AND METHODS: The research was conducted on a sample of 304 respondents. Data were collected through an online survey with 14 questions, and were analyzed using SPSS and Microsoft Excel. RESULTS: Out of all 304 respondents, 213 are women and 91 are men. The largest number of respondents (60%) have completed high school, while 40% have a higher professional degree. Knowledge of providing first aid in case of cardiac arrest showed that 56% of respondents had satisfactory knowledge (6 or more points). No significant difference in knowledge was found between respondents with different levels of education. Respondents younger than 35 showed significantly better knowledge than those older than 35. Regarding readiness, 173 respondents expressed their willingness to provide first aid in case of cardiac arrest, while 74 respondents are ready to use an AVD device. CONCLUSION: Although the layman's knowledge of first aid in cardiac arrest is satisfactory, there is room for further improvement through education. It is necessary to motivate citizens to acquire and improve knowledge in order to increase the survival rate in cases of cardiac arrest.