Nursing, as a humanitarian science, offers its services, on the comprehensive care of patients. Each nurse handling, involves the possibility of error. Meurier appointed nursing error as "any act, any decision or omission by a nurse, assessed as incorrect, by more experienced colleagues, and have adverse consequences for patients". Medication errors are the most common category of nursing errors. They affect health, patient safety and also have a high economic impact to health systems of each country. Aim: The present study investigated the causative factors of nursing errors, the frequency of medication errors and the ways of reporting, recording and managing these errors in the hospitals of Greece. Method: For the purpose of this study, a descriptive cross-sectional design was used. The sample consisted of 176 registered nurses, from eight public and three private hospitals, working in the ICU and their duties included the administration of drugs. Data collection was performed using an anonymous structured questionnaire that included demographic characteristics of the sample and closed questions about the factors implicated in the occurrence of errors and their management. To investigate the existence of correlation between demographics and various questions referred to the management of errors by nurses, the criterion of heterogeneity X2 of Pearson was used and to check for correlation between questions that reflect the participants' views on working conditions and management of errors, the non-parametric correlation coefficient of Spearman (Spearman rho) was applied. The statistical analysis was performed using SPSS 17 software. Results: After statistical analysis of data, the most important causative factors for the occurrence of errors are the nursing workload (78.9%), the distraction of nurses (75.8%) and the burnout (56.8%). More than 9 out of 10 nurses have made errors in drug administration (91.5%), especially with the wrong dose (34.7%) and the wrong time of administration (32.4%). Finally, 86.6% of the respondents believed that the official record of nursing errors would improve health care provision. Conclusions: Nursing errors are a reality for Greek hospitals. The major causative factors are workload, burnout and frequent interruptions to nurses during preparation and administration of medication. Although nurses seem to want the official record of errors, much still refuses to reveal any, while in Greece there is no formal mechanism to manage these errors.