The hemodynamic effects of combined therapy utilizing sodium nitroprusside (SNP) and nitroglycerin (TNG) were compared with those of TNG therapy in patients who underwent coronary artery bypass grafting (CABG). Of 58 patients who received catecholamine infusion to maintain hemodynamics after CABG, 17 had perioperative myocardial infarction (PMI (+) cases) and the other 41 had not PMI (PMI (-) cases). 26 of 41 patients (PMI (-) cases) received nitroglycerin therapy (NTG group) and the other 15 patients received combined therapy (SNP + NTG group). 11 of 17 patients (PMI (+) cases) received NTG therapy and the other 6 patients received combined therapy. The hemodynamic valuables, which were studied, were as follows; cardiac index, stroke volume index, left ventricular stroke work index, systemic vascular resistance index, pulmonary vascular resistance index, and deep core temperature. SNP + TNG group revealed significantly lower systemic vascular resistance index and pulmonary vascular resistance index than TNG group in PMI (-) cases. In PMI (+) cases, SNP + TNG group revealed significantly higher cardiac index, stroke volume index, left ventricular stroke work index, and significantly lower pulmonary vascular resistance index than TNG group. These findings demonstrate that combined therapy can obtain more secure vasodilation than TNG therapy.