Recently, there have been many reports of monitor alarm-related accidents, and we believe this is due to alarm fatigue. To solve this problem, we established a transdisciplinary monitor alarm control team (MACT) at our hospital and conducted an intervention study for the Cardiovascular Department ward. We evaluated the number of alarms before and after the intervention and found that the number of alarms decreased from 1,263.4±453.4 before the intervention to 264.1±128.4 after the intervention.