Japanese guideline for the safe handling of anticancer drugs recommends a closed system drug transfer device (CSTD). We gradually introduced the PhaSeal TM system from preparation to administration of all anticancer drugs to inpatients on holidays as well as weekdays. We evaluated whether the CSTD handling of 36 pharmacists was appropriate or not and also retrospectively compared outcomes before and after the introduction of CSTD. In nine pharmacists who had more than 4 items of an inappropriate handling of CSTD, the median noncompliance ratio after retraining was significantly improved from 4 to 1 items (P = 0.008). We subsequently administered a questionnaire for 36 pharmacists. The customer satisfaction analysis indicated two issues for improvement: anxiety over appropriate preparation on the double audit system of pharmacists and anxiety over miss priming after liquid sensor. On the other hand, the median introduction ratio per day of CSTD between February and April 2016 and between September and October 2016 was significantly increased on weekdays and holidays (P < 0.001 and P < 0.001, respectively). In addition, the median preparation time per day between February and April 2016 and between September and October 2016 was not significantly increased on weekdays and holidays (P = 0.514 and P = 0.423, respectively). These results suggest that our training for pharmacists contributed to an appropriate handling of CSTD, resulting in the safe handling of all anticancer drugs to inpatients on weekdays as well as holidays and the risk management of pharmacists without increase of the preparation time.