BackgroundSplenic injury due to chest compressions is a rare and fatal complication that occurs immediately after cardiopulmonary resuscitation.Case PresentationCardiopulmonary resuscitation was carried out using a mechanical chest compression device in a 74‐year‐old Japanese female patient who underwent cardiac arrest. Computed tomography postresuscitation revealed bilateral anterior rib fractures. Other traumatic findings were not observed. Coronary angiography revealed no new lesions; the cause of the arrest was hypokalemia. She received mechanical support with venoarterial extracorporeal membrane oxygenation and multiple antithrombotic agents. Her hemodynamic and coagulative condition became life‐threatening on day 4; abdominal ultrasound revealed massive bloody ascites. Only a minor splenic laceration was observed intraoperatively, despite massive bleeding. Furthermore, her condition stabilized after splenectomy and blood transfusion. Venoarterial extracorporeal membrane oxygenation was discontinued on day 5.ConclusionIn patients with postcardiac arrest, delayed bleeding due to minor visceral injury should be considered, particularly for coagulation abnormalities.