AbstractAlthough adverse events related to extracorporeal membrane oxygenation have been reported, epidemiological data on life-threatening events are insufficient to study the causes of such adverse events. Data from the Japan Council for Quality Health Care database were retrospectively analyzed. The adverse events extracted from this national database included events associated with extracorporeal membrane oxygenation reported between January 2010 and December 2021. We identified 178 adverse events related to extracorporeal membrane oxygenation. At least 41 (23%) and 47 (26%) accidents resulted in death and residual disability, respectively. The most common adverse events were cannula malposition (28%), decannulation (19%), and bleeding (15%). Among patients with cannula malposition, 38% did not undergo fluoroscopy-guided or ultrasound-guided cannulation, 54% required surgical treatment, and 18% required trans-arterial embolization. In this epidemiological study in Japan, 23% of the adverse events related to extracorporeal membrane oxygenation had fatal outcomes. Our findings suggest that a training system for cannulation techniques may be needed, and hospitals offering extracorporeal membrane oxygenation should perform emergency surgeries.