Medication errors are the second most common cause of adverse patient safety incidents and the single most common preventable cause of adverse events in medical practice. Given the high human fatalities and financial burden of medication errors for healthcare systems worldwide, reducing their occurrence is a global priority. Therefore, appropriate policies to reduce medication errors, using national data and valid statistics are required. The primary objective of this study was to provide a national ‘characteristic profile’ of medication error-associated adverse drug reactions (ADRs), which are also known as preventable ADRs (pADRs). A retrospective study of pADR reports submitted to the national pharmacovigilance center (PCV) within Iran’s Food and Drug Administration was conducted over a 2-year period (2015-2017). Preventability Method (P-Method), which is a standardized tool developed and recommended by the World Health Organization (WHO), was used for preventability assessment. The results of the analyses revealed that while the number of pADRs increased from year one to two (601 to 630), their proportion out of all ADRs per year decreased (7.32% to 6.44%). The percentage of pADRs was higher in females (61.01%) and adults (83.27%), and the highest number of reports were received by nurses (71.57%). Having ‘a documented hypersensitivity to an administered drug or drug class’ was the most common preventable factor in both years (61.23% and 54.29% respectively), and ‘anti-infectives used systemically’ were the medication class which primarily contributed to both serious (53.29%) and non-serious pADRs (39.19%). The specific characteristics of medication errors associated with ADRs from this study, especially the preventable criteria which led to their occurrence, can help devise more specific preventative policies.