that health professionals be familiar with cardiac arrest rhythms so that they can easily recognize and react. Aim: To evaluate the nurses' level of knowledge in cardiac arrest rhythms, as well as the potential factors affecting it. Material and Methods: Prospective cross-sectional study has been conducted in four (4) hospitals located in Attica, Greece, between July and September 2019. A hundred and eighty-four (184) nurses participated in the survey as subjects. The collection of data was taken by a special self-completion questionnaire, which was completed voluntarily by the participants. The correct answer of twelve (12) questions, out of sixteen (16) in total, (75% of the questionnaire) was defined as adequate knowledge level. Descriptive statistics, comparisons with non-parametric tests (Chi-squared test [χ2], Mann-Whitney, Kruskal-Wallis and Spearman) and Logistic Regression with nurses' knowledge level as the dependent variable have been used (SPSS v.24, p≤0.005). Results: One fourth (25%) of the participants seemed to have an adequate knowledge level. The level significantly varied depending on the subject's postgraduate institution (p=0.046), the work department (p=0.05), the frequent observation of a patient's continuous cardiogram (p=0.000) and the self-evaluation level when it comes to recognition and treatment. In multivariate logistic regression, it was found that nurses who rarely monitor a patient's cardiogram had a 95.2% smaller chance to be efficient than those who daily check it over (OR:0.048, 95% CI: 0.005-0.417, p=0.006). Conclusion: The level of recognition and reaction to cardiac arrest rhythms was low among nurses. Taking this into account, it is important for nurses to be systematically and constantly educated in cardiac arrest rhythms.