OBJECTIVES: Medication errors are unintentional errors in how medicines are prescribed, dispensed, administered, or monitored while controlled by a healthcare professional, patient, or consumer. Leendertse et al (2008) reported that 5.6% of acute hospital admissions are medication-related, of which 46.5% were potentially preventable. This study estimated the costs related to medication errors that lead to avoidable hospitalizations in Belgium. METHODS: Based on the incidences from Leendertse et al (2008), the number of hospital admissions due to avoidable medication errors in Belgium was determined. The total avoidable costs attributable to medication errors was estimated, by multiplying the number of avoidable hospitalizations with the average cost of a hospital stay, calculated using the online official database of the Technical Cell  (data from 2011). Costs were inflated to 2014. RESULTS: The estimated average cost of a hospital stay in Belgium was €4,886. Based on 2.6%, the incidence rate of total hospital admissions attributable to medication errors, 42,797 hospital admissions that could have been avoided due to medication errors were estimated. Avoiding these hospitalizations would produce potential savings of €209Mn per year. CONCLUSIONS: This study shows that the economic and health burden of preventable medication errors is high. As such, a synergic approach is warranted nationally and across national borders. This should entail communication and involvement from all different stakeholders (medical doctors, pharmacists, hospitals, national and international pharmacovigilance organizations) in the provision and delivery of care.