The extension of HCC with tumor thrombus through the hepatic veins into the right atrium can cause sudden death due to heart failure and pulmonary embolism, even though the primary tumor may be relatively localized. We report a case of hepatic resection and tumor thrombectomy of hepatocellular carcinoma with tumor thrombus extending into right atrium using cardiopulmonary bypass and total hepatic vascular exclusion. A 65-year-old man, with a diagnosis of left liver mass, visited Yeungnam University Hospital. The patient had no noticeable edema in the lower extremities, but had dyspnea on exertion. Laboratory studies revealed a platelet count of 162 K/uL, total bilirubin of 1 mg/dL, albumin of 4.1 g/dL and a prothrombin time of 14.7 second. In addition, the retention of indocyanine green at 15 min was 13.5 %. The patient was anti-HCV was positive and his levels of alpha-fetoprotein and PIVKA-2 were 6.45 ng/mL and 582 mIU/mL, respectively. An abdominal CT scan, hepatic angiogram and echocardiogram showed a 4 cm sized HCC in the left lobe and a 4 to 5 cm sized tumor thrombus extending into the right atrium through the left and middle hepatic veins. No distant metastasis was detected in other studies. Total operative time, total duration of cardiopulmonary bypass and cardioplegic time were 13 hours, and 55 and 24 minutes, respectively. The total hepatic vascular exclusion time was 18 minutes. Unfortunately, the patients died 2 months later due to ARDS without being discharged from hospital.