Objective: To investigate the effects of restrictive fluid regimen during major abdominal surgery in pediatric patients. Background: In adults, a restrictive and goal-directed regimen as opposed to a liberal-fluid regimen results in better outcomes after various major surgical procedures. The different ratio of body fluid distribution in pediatric patients from those of adults may influence different needs of fluid. Methods: This stratified, randomized, controlled trial was conducted in 25 pediatric patients (mean age <3years) undergoing major abdominal surgery. Patients were allocated to two groups based on their perioperative fluid management. control group' received maintenance plus deficit plus interstitial space replacement plus ongoing loss, whereas restrictive group' had a similar treatment, but were given no interstitial space replacement. Intraoperative fluid resuscitation was guided by hemodynamics and base excess. Parameters recorded included hemodynamic variables, the volume and type of intravenous fluid, blood chemistry (including lactate, base excess, and electrolyte), chest X-ray, body weight, complications, and return of bowel function. Results: Patients in control group needed significantly less additional fluid for resuscitation compared to restrictive group (0.62 +/- 3.51 ml.kg(-1).h(-1) vs 5.04 +/- 4.16 ml.kg(-1).h(-1); P=0.012). In restrictive group, heart rates were higher (P=0.012) and base excess showed more negative results (P=0.049). There were no differences between the groups in terms of the total volume requirement, postoperative kidney function, chest X-ray, variation of body weight and the postoperative outcomes. Conclusions: Volume preload corresponding with an estimated interstitial space replacement was suitable for application to pediatric patients undergoing major abdominal surgery.