Dilated cardiomyopathy complicated by a pedunculated and mobile left ventricular thrombus on ruptured false tendons. A 68-year-old man was admitted with congestive heart failure. He was treated with diuretics and digitalis; thereafter, the two-dimensional echocardiogram suggested a pedunculated and mobile left ventricular thrombus. He underwent surgical thrombectomy because of the high risk of systemic embolization. To our knowledge, this is the first case of dilated cardiomyopathy with a mobile left ventricular thrombus that was attached to ruptured false tendons. 