BACKGROUND: Cisatracurium, one of 10 isomers of atracurium, undergoes pH and temperature-dependent Hofmann elimination in plasma and tissues. Physiologic changes may affect the pharmacodynamics of neuromuscular bldegrees Cking agent during pregnancy. So, we compared the difference in the infusion rate and its spontaneous recovery of cisatracurium between full-term pregnant and nonpregnant women. METHODS: Muscle relaxation of full-term pregnant(group I, n=10) and nonpregnant(group II, n=10) women was maintained by continuous infusion of cisatracurium to keep 1st twitch response of train-of-four(TOF) at 5~10% of control. After discontinuation of infusion, recovery index was measured without reversals using the accelerograph. RESULTS: The infusion rate of cisatracurium in group I(1.25+/-0.16 mcg/kg/min) was not significantly different from that in group II(1.31+/-0.22) and recovery indices were not different between two groups(10.7+/-2.0 vs. 11.6+/-1.9 min). CONCLUSION: The infusion rate of cisatracurium in parturients to maintain surgical relaxation is not different from that in non-parturients. For Cesarean section, the usual infusion rate of cisatracurium is recommeneded to achieve the adequate surgical relaxation.