Background & Aim: Medication errors are among the factors that threaten the safety of patients, and increase the mortality rate and hospital costs. This study was aimed to investigate the factors affecting the incidence of medical errors from the perspective of nurses in Khorramabad Shohada Ashayer hospital.
 
Materials and Methods: In this cross-sectional study, 65 nurses in various wards of the   hospital were included by non-probability convenience sampling. By using a self made questionnaire the nurses views on the factors affecting medication errors were evaluated. Validity of the questionnaire was measured by expert opinions and in order to assess it’s reliability; split half method was used. The areas that were covered by the questionnaire include management processes errors, the working conditions of nurses and doctors, nursing errors, factors associated with patients, medication errors related to the characteristics of drugs, and physical environment condition of departments. In the questionnaire each factor as categorized ''very important'', ''medium importance'', ''low importance'', and ''of no importance'', these were rated from 1-4. Data were described using means and percentages of frequency.
 Results: The average age was 35.2 years. 48.2% of the subject stated that during their professional nursing careeas they had comitted medication error. The average frequency of medication error was 3.4 ± 1.8 annually. From the view point of nurses, management processes were the most frequent causes of medication errors. Most of the participants rated these factors as the most common causes of medication error: shortage of nurses to patients(73.8%), fatigue caused by overwork(72.8%), presence  of the patients  family (70.8%), lack of motivation because of discrimination (61.5%), economic problems(58.8%), illegible hand writing of  practitioners(50.8%) and the working shift(49.2%).Were rated most  as the  important factors in medication errors .
 Conclusion: Improved management processes and effective management practice in hospitals by proper planning to ensure adequate staffing; increasing nurses knowledge, medical skills, and motivation; and adjusting a nurses working conditions can play a significant role in preventing medication errors.