Hypotension during spinal anesthesia for cesaresn section remains as a common and serious complication despite the use of uterine displacement and volume preloading. This study was designed to compare the efficacy of the speed of crystalloid preload for reduc- ing the incidence of hypotension during spinal anesthesia for elective cesarean section. Twenty ASA I parturients were randomly allocated to receive 20ml/kg of crystalloid over either 20min (group 1) or 10min(group 2) before spinal anesthesia. Both groups showed a significant increase in central venous pressure during and immediately after preload, but there was no significant difference between the groups. Six patients in group 1 developed hypotension(a decrease in systolic pressure below 100mmHg and a fall of 20% from baseline values) and so did seven patients in group 2. We concluded that rapid crystalloid preloading did not reduce the incidence of hypotension during cesarean section under spinal anesthesia and its effectiveness in questionable.