Background: There have been few reports on the development of acute myocardial infarction (AMI) during chemotherapy, therefore the causes and preventive measures have not been fully evaluated. We report a case of pancreatic undifferentiated carcinoma in a patient who suffered cardiopulmonary arrest (CPA) during paclitaxel and carboplatin (TC) therapy. The cause of death was diagnosed as AMI at autopsy. Case: A 69-year-old man was diagnosed with stage IVb pancreatic tail cancer with a histology of suspected undifferentiated carcinoma. It was associated with invasion to stomach and transverse colon, and multiple metastases to liver and peritoneum. He took medications for hypertension, hyperlipidemia, diabetes, and prior cerebral infarction, while he had no history of heart disease. We started the first cycle of TC therapy. We performed both electrocardiography and echocardiography at baseline, and detected atrial fibrillation, right bundle branch block, and mild diffuse hypokinesis. On the fifth day, he began to complain of nausea and appetite loss, which worsened gradually. On the seventh day, he suffered CPA after vomiting at home. He was transported by ambulance but was pronounced dead after a failed resuscitation. Initially, we assumed that he died from suffocation from aspiration. However, our final diagnosis of the direct cause of death was AMI, according to autopsy findings of fresh and extensive MI at the interventricular septum and a high possibility that the aspiration occurred after death. The histological diagnosis of the pancreatic tumor was confirmed undifferentiated carcinoma. Discussion: We speculated that an underlying coronary arteriosclerosis and subsequent toxicities such as volume depletion and anemia might have caused the AMI. Special attention should be given to the management of coronary risk factors and toxicities, regardless of the prevalence of cardiotoxicity, when chemotherapy is administered to patients with multiple coronary risk factors.