A 79-year-old man was admitted for thoracoabdominal aortic aneurysm repair. He had already twice undergone coronary artery bypass grafting, 19 and 2 years previously. The value of the ejection fraction of the left ventricle was 36%, measured by ventriculography; and transthoracic echocardiography revealed moderate aortic valve regurgitation. In the presence of aortic valve regurgitation or coronary artery disease, myocardial perfusion under hypothermic fibrillatory arrest may be significantly impaired. Therefore, to maintain a beating heart we used separate perfusions of the upper and lower body that enabled individual temperature control of each organ. The femoral and axillary arteries were cannulated, and a long cannula was inserted into the right common femoral vein and positioned in the right atrium. Cardiopulmonary bypass was established, and the upper body was mildly cooled until the pharyngeal temperature was 33°C, while the lower body was cooled until the bladder temperature reached 20°C. Mild hypothermia of the upper body maintained the beating heart, and deep hypothermia in the lower body provided adequate protection to the spinal cord. Furthermore, in a case of aortic valve regurgitation and low left ventricular function, left ventricular venting is essential for the heart. However, it was difficult to insert the venting tube through the apex of the left ventricle or through the left inferior pulmonary vein; therefore, we selected the left main pulmonary artery for left ventricular venting, and maintained a non-working beating heart. After cardiopulmonary bypass was discontinued, cardiac function was good although a bleeding tendency became apparent. Postoperatively, the maximum dose of dopamine we needed was only 3γ. There were no remarkable complications and the patient was discharged on postoperative day 30. This experience suggests that pulmonary artery venting and separate perfusion of the upper and lower body to individually control organ temperatures is a useful procedure for thoracoabdominal aortic aneurysm repair in patients with low left ventricular function.