Wakefield et al. (1996) and was modified by the researchers. It contained 65 questions; 29 items regarding reasons why medication errors occur, 16 items regarding reasons why medication errors not reporting and 20 items regarding what percentage of each type of medication error actually reported on units which divided into 9 items for non intravenous and 11 items for intravenous medication administration errors. Results: This study suggested five categories for reasons of why MAEs occur and three categories for reasons of why MAEs not reporting. Nurses perceive low percentages of MAEs reporting. Emergency room was more likely to report medication administration errors than other units. Conclusion