This study investigated the perspectives of newly graduated and experienced nurses concerning medication errors. This is a descriptive cross-sectional study conducted in a military education and research hospital in Turkey, which was performed between July and August 2009. Totally, 169 nurses were involved in this study: 87 were new graduates and 82 were experienced nurses. The Modified Gladstone's Scale of Medication Errors was used to collect data on rates, causes and reporting of medication errors. The two highest perceived causes of medication errors were nurse exhaustion and nurse distraction. Most medication errors were preventable errors. The reasons for error occurrence and failure to inform co-workers of medical errors were examined. Implications: Training nurses to understand the causes of medication errors and related prevention methods should be provided to newly graduated nurses, and continuous training should be provided.