We evaluated the effect of intraoperative vasodilator therapy on the occurrence of postoperative shivering and the fall of core temperature during 37 abdominal operations by the stepwise multiple regression analysis. As the vasodilator, we used PGE1 at the dose of 0.02-0.05 microgram.kg-1.min-1. In the vasodilator group, postoperative peripheral surface temperature was high and the occurrence of shivering was low. And intraoperative and postoperative core temperatures were not affected by that therapy. From these results, we conclude that intraoperative vasodilator therapy suppressed the occurrence of postoperative shivering without a fall of core temperature.