Background & Aim: Administration of medications is an important part of treatment and care provided by nurses. Medication errors can create serious problems to patients and health system. The aim of this study was to determine the reasons of medication errors and the barriers of error reporting from nurses' viewpoints.

Methods & Materials: In this study, we randomly selected five hospitals in Tabriz and Maragheh. Then, 200 nurses who were randomly selected for the study completed the study questionnaire. The questionnaire included 21 items about medication errors and 19 items about the barriers of error reporting, based on five degree Likert scale. Collected data were analyzed using SPSS-15.

Results: In this study, from the viewpoint of nurses, the most important reasons of medication errors were hospital units (3.70±0.84), shortages of nursing staff, nuring burn-out and high workload. Regarding barriers of error reporting, the most cited barriers were management factors (3.78±0.89), fear of legal issues, inappropriate definition of medication error and inappropriate reactions of authorities.

Conclusion: We recommend increasing the number of nursing staff, adjusting the workload of nursing staff, using special forms for reporting errors and providing an atmosphere of intimacy between authorities and staffs.