We studied the effects of prostaglandin E1 (PGE1) on hand-foot temperature gradients (foot temperature-hand temperature) induced by lumbar epidural anesthesia. Thirty-six ASA class 1 patients undergoing rotatory acetabular osteotomy were randomly assigned to receive 0 gamma (n = 13), 0.005 gamma (n = 10) and 0.02 gamma (n = 13) of PGE1. Thermometric probes were placed on the palm and sole of each patient. Bladder temperature was also monitored to evaluate the change of core temperature. Epidural catheter was indwelled at the level between L2 and L3 prior to induction and 2 % lidocaine was administered epidurally. All patients were warmed by water blanket at 37 degrees C and fluids for infusion warmed at 37 degrees C. Humidity and moisture exchanger was placed in breathing circuit. Hand-foot temperature gradients of patients given 0 and 0.005 gamma of PGE1 increased to 2.8 +/- 1.5 and 2.3 +/- 2.3 degrees C at extubation, respectively. In contrast, temperature gradient of patients given 0.02 gamma of PGE1 was 0.0 +/- 1.8 degrees C (P < 0.01). There was no difference among the values of bladder temperature in each group. The effects of PGE1 on mean arterial pressure, heart rate and central venous pressure were minimal. These data suggest that 0.02 gamma of PGE1 administration is effective to reduce hand-foot temperature gradient during epidural anesthesia.