Safety and quality care of patients are key aspects and the mean goals of effective health care systems. The reality that medical treatment can harm patients is one that has had to be addressed by the healthcare community in recent years. This study aimed to explore nurses' perception of factors contributing to medication administration errors and reasons for which medication administration errors are not reporting. Descriptive exploratory cross-sectional design carried out to achieve the study aim. The study was conducted in two regional hospitals in Egypt. They had a total bed capacity of 512 beds distributed over three units (emergency, intensive care, and surgical units). A convenient sample of 146 nurses distributed in the morning and afternoon shifts in the units mentioned above was recruited in this study. Medication Administration Errors (MAEs) Reporting Scale used to collect data regarding the nurses' perception of factors contributing to the MAEs. The participants were ranked the most important factor for MAEs occur system reasons (24.73±1.46), followed by nurses staffing as the second reason of MAEs (24.11± 2.25). Third, fourth, and fifth-ranked reasons were physician communication (13.37± 2.7), medication packaging (12.84±1.87), transcription-related (8±0.1), respectively. Finally, pharmacy processes (6.9±2.93) viewed as the least factor for the frequency of MAE. The findings of the present study concluded seven perceived reasons for MAE, namely system reason, nurses' staffing, physician communication, medication packaging, transcription, and pharmacy process. The study recommended the development of active quality assurance systems in all health care environments concerning medications and drug administration.