A 67-year-old woman underwent CABG because of severe triple vessel disease. She could not wean from CPB in spite of full inotropic drugs and IABP support due to right ventricular failure probably caused by the perioperative right ventricular infarction. Right heart bypass (RHB) with a centrifugal pump was used. Finally she could wean from CPB and took an uneventful postoperative course except mediastinitis. During 5 days of RHB operation ACT was maintained between 180s and 200s by systemic heparinization. RHB with a centrifugal pump is a reliable method to assist a failing right ventricle.