Sudden cardiac arrest is one of the leading causes of death in Europe. Bystanders’ early Cardio-Pulmonary Resuscitation (CPR) may double or triple survival rates of out-of-hospital cardiac arrest victims. Aim: To investigate nurses’ attitude, in starting or not CPR and also the most frequent reasons that deter them from engaging in. Materials and Methods: The study had a sample of 177 nurses and assistant nurses that were working in nine hospitals of Athens. Nurses filled out the same, predetermined questionnaire, voluntarily and anonymously. The collected answers were analyzed with the help of the statistical program SPSS v.16, using x2 and Kendall’s Tau-B methods. Results: From 177 participants, 78% (137) were women and 22% (40) men with mean age 31 years (±7). According to their education, 16% (28) were Assistant Nurses, 79% (140) Registered Nurses (ATEI, AEI) and 5% (9) Nurses had an MSc diploma. Nurses that had been recently trained in certified BLS courses felt more confident and were more willing to start CPR in a known victim (p=0.004) and in an unknown victim (p=0.02) comparing to nurses that had been trained a long time ago or never. Most frequent reasons nurses reported that deter them from starting CPR are the fear of a possible lawsuit (43%), the fear of harming instead of helping (30%) and the fear of infectious transmission from victim to rescuer (15%). The fear of harming correlates considerably with lower ages (the younger the nurse the more is afraid, p=0.04) and also correlates substantially with the training in a certified CPR course (the more a nurse is trained, the less is afraid, p<0.001). Accordingly, the fear of infection diminishes as long as the CPR training is repeated (p=0.03). Conclusions: According to the results, there is a necessity of continuous education and re-education of nurses, in certified Basic Life Support programs. With frequent and specialized training, nurses will show more willingness to engage in an out-of-hospital arrest situation, in a familiar or unknown victim and, moreover, fears that deter them from starting CPR are remarkably reduced.