In a 17-year-old youth, exploratory laparotomy for acute abdominal pain was complicated by circulatory arrest related to pulmonary embolism. Echocardiography after resuscitation revealed a hitherto "silent" right atrial myxoma, fragmentation of which had blocked the right atrioventricular ostium, causing the pain. Operation was successful. As only a few similar cases have been reported, pulmonary embolism due to fragmentation of a right atrial myxoma may account for some unexplained sudden deaths beyond medical help.