BACKGROUND: Perioperative hypothermia is a common problem during both laparotomy and laparoscopic surgery. Hypothermia during laparoscopic surgery is related to the use of irrigation fluid and the large volume of CO2 for maintaining pneumoperitoneum. The aim of this study is to estimate whether the use of warm irrigation fluid can reduce the incidence of hypothermia and the decrease of body temperature. METHODS: Forty-two female patients undergoing elective laparoscopic surgery were randomly divided into 2 groups. Group 1 (n = 20) was given an ambient temperature irrigation fluid and group 2 (n = 22) a warm irrigation fluid. The core esophageal body temperatures of all the patients were measured every 10 minutes for 70 minutes. Body temperature 10 minutes after induction was a control value. The degree of body temperature decrease was measured, and the incidence of hypothermia was recorded. RESULTS: The incidences of hypothermia in group 2 were decreased significantly 60 and 70 minutes after induction, compared with those of group 1. The degree of body temperature decrease was revealed to be significantly different between the two groups starting 50 minutes after induction. CONCLUSIONS: The use of warm irrigation fluid during laparoscopic surgery can reduce the incidence of hypothermia and degree of body temperature decrease.