Background and Objective: The risk of medication errors in internship nursing students is due to independence in practice that identification of medication errors is essential for protecting patient safety. The aim of this study was to investigate the types and causes of medication error and barriers in reporting it in internship nursing students.
Materials and Methods: This Descriptive-analytic study done with the census method on 87 internship nursing students.   The researcher with referring to the hospitals related to Hamadan University of Medical Sciences delivered to students a four parts questionnaire which includes demographic data, types of drug error within three months, factors affecting on incidence error and reasons to refuse to report the error. The data were analyzed with SPSS16 using descriptive and Chi-square and independent t-test.
Results: Medication errors occurred in 14.9% of students and did not have any significant relation to demographic information. The most error occurred in the implementation of the drug delayed or sooner than the prescribed time (10.5 ± 13.43), the most effective factor is the lack of knowledge of medicine (2.43±1.27) and the most important contributing factor was high workload (2.84±1.54). The most important reason in refuse to report errors was raised insufficient support for students (2.96±1.22).
Conclusion: The lack of pharmaceutical knowledge and stress leads to the occurrence of drug error. Insufficient support for students is an important factor in preventing error reporting. Therefore in order to prevent and improve the patient's safety it is suggested to emphasis the pharmaceutical information in nursing education and providing the arrangements for supporting students in reporting errors.