The goal of this research was to find out the effect of dispensing error prevention program on the incidence of the error in a university hospital pharmacy in Daegu. Dispensing error in this research was defined as the error identified during double-checking process, so it does not mean that the wrong dispensing was administered to patient. Drug name error was the most frequently found error, accounting for about one third of all dispensing errors, and was followed by counting error, strength error, dosage form error, and others. Similar drug name was identified as the most frequent reason for the error, taking up about two thirds of all drug name errors. In this research, six months of dispensing error prevention program resulted in statistically significant reduction of dispensing error by 42 percent. Therefore, it is recommended that hospital pharmacy implement such prevention program regularly to reduce the incidence of the error. Finally, it appears that drug approval authority should closely check the similar drug names and have power to command pharmaceutical company to change the name if pertinent.