Objective: To prevent the mis-prescription of drugs that differs from the true intention, it is important to understand the factors underlying mis-prescription. In this study, we focused on drug prescription errors caused by drug name similarities and compared drug dispensing errors by pharmacists to clarify their characteristics.Methods: We extracted cases of drug prescription and dispensing errors caused by drug name similarity from "near-miss events from pharmacies" reported from March 2020 to October 2022, which were curated by the Japan Council for Quality Health Care. By comparing the characteristics of pairs of "drugs intended to be prescribed or dispensed" and "drugs that were mis-prescribed or misdispensed" (called as drug name pairs), we analyzed trends in drug prescription errors caused by drug name similarity. Specifically, we evaluated drug name similarity (calculated using m2-Visually Weighted Head and Tail-weighted Fragmentary Pattern-Based Measure; m2-vwhtfrag), the number of initial common characters, and drug efficacy similarity (evaluated by drug efficacy classification number) in drug name pairs and assessed their occurrence among drug prescribing and dispensing error cases.Results: From the "near-miss events from pharmacies," 234 cases of prescription errors and 152 cases of dispensing errors caused by drug name similarity were extracted. Drug prescription errors exhibited higher drug name similarity (i.e., higher values of m2-vwhtfrag) and more initial common characteristics than drug dispensing errors. In contrast, drug prescription errors showed a lower consistency in drug efficacy similarity.Conclusion: In this study, we found that prescription errors by physicians were more likely to be influenced by drug name similarity and less likely to be influenced by drug efficacy similarity compared to the dispensing errors by pharmacists. These findings are reasonable, considering the characteristics of the prescription ordering systems.