The clinical experience with a new fluid therapy in children with acute brain edema complicated by infectious disease is reported. The clinical data of a retrospective group of 192 patients and a prospective study of 1,302 and 2,279 patients is summarized. One method of fluid therapy for children with acute brain edema is traditional; fluid intake is restricted to less than 1,200 mL/m(2) daily (60 mL/kg daily). Another method is the new fluid therapy regimen used in our prospective study, in which dehydration and fluid replenishment are individualized. On the first day the fluid intake of patients who survived varied from 40 to 208 mL/kg daily. The mortality rate in the two prospective groups was 19.66% in 1,302 patients and 17.2% in 2,279 patients, significantly lower than the 63.5% in the retrospective group (192 patients) (P <0.001). This result indicates that a wide range of fluid intake for children with acute brain edema is allowable during the first days of treatment. The appropriate dehydration and fluid replenishment should be individualized based on close observation of the patient's condition.