A 47-year-old man with advanced pancreatic carcinoma underwent total pancreatectomy with resection of the involved portal vein. His postoperative course was complicated by a couple of cardiac arrest episodes. The first episode occurred seven weeks after surgery during drip infusion of CDDP, and later on during the thirteenth week after surgery. There was no apparent cause for those episodes. On both occasions resuscitation was performed adequately. The second arrest was followed by deep inverted T waves on ECG, however, not by elevation of serum CPK-MB. Because of this, myocardial infarction was ruled out. The diagnosis of cardiomyopathy was made possible through the discovery on the echocardiogram of a hypertrophied left ventricle with thick interventricular septum. Then, on catheterization, myocardial squeezing in the left anterior descending coronary artery was noticed. Finally, histological findings concerning the biopsied cardiac muscle led to the same diagnosis. Cardiac arrest in this case seemed to be due to arrhythmia caused by cardiomyopathy. Echo cardiography should be routinely used as part of the examination prior to extended major surgery.