Hypothermia is common during surgery in regular operating room (OR) temperature. The effect of increasing the OR temperature to 24 degrees C coupled with simple warming measures to maintain normothermia in both pediatric and adult patients during living donor liver transplantation (LDLT) was evaluated. One hundred patients undergoing LDLT were separated into pediatric (GI) and adult (GII) groups. Nasopharyngeal temperature (NT) at each hour for the first 6 h, at the time of anhepatic phase, 5 and 30 min after reperfusion, and each hour for the last 2 h of the operation was recorded, compared and analyzed. A significant difference in core temperature variation was noted between the two groups. GI tended to be hyperthermic, while GII remained mildly hypothermic throughout the procedure. A sudden decrease of NT was observed in both groups during the anhepatic and reperfusion phases. Correlation between liver graft weight over recipient body weight ratio rather than the graft weight itself was found in GI, but no such correlation was found in GII. OR temperature of 24 degrees C, together with simple active and passive warming measures are more effective in maintaining normothermia during liver transplantation in pediatric patients than in adults.