Background Medication Errors are among the most common types of incidents reported in Australian and international hospitals. There is no uniform method of reporting these errors and no uniform method of reducing them. This study aims to identify the incidence, time trends, types and factors associated factors with medication errors in a large regional hospital. Methods A five-year cross sectional study Results The incidence of medication errors was 1.05 per 100 admitted patients. The highest frequency of errors was observed during the colder months of May to August. When distributed by day, Mondays and Tuesdays had the highest frequency of errors. When distributed by hour of the day, time intervals from 7am to 8am and 7 pm to 8pm showed a sharp increase in the frequency of errors. 1088 (57.8%) MEs belonged to ISR 4 and 787 (41.8%) belonged to ISR 3. There were 6 incidents of ISR level 2 and only 1 incident of ISR level 1 reported in the last 5 years. Administration only errors were the most common accounting for 1070 (56.8%) followed by prescribing only errors (433, 23%). High risk medications were associated with half the number of errors, the most common of which were narcotics (17.9%) and anti-microbials (13.2%). Conclusions Medication errors continue to be a problem faced by hospitals internationally. Inexperience of health professionals and nurse-patient ratios might be the fundamental challenges to overcome. Specific training of junior staff in prescribing and administering medication and nurse workload management could be possible solutions to reducing MEs in hospitals.