Prescriptions for injectable drugs are frequently modified just before dosing due to sudden changes in patients’conditions.It is therefore highly desirable to have an efficient system that facilitates the thorough management of injectable drugs.In this study, we created an inventory management system incorporating a commercially available automatic dispenser for injectable drugs (YS-APR) and evaluated its effectiveness in daily pharmaceutical care.When using the system, the value of the stock in the automatic dispenser was approximately 50% of the former level, and it could check JAN codes at the time of dispensing which avoided mistakes.There was no significant difference in stocking times between before and after introducing it.Our system not only improved inventory management but also contributed to reducing the risk of mistakes in dispensing injectable drugs.