Since 1977, eight children have had major liver resections with the aid of normovolemic hemodilution anesthesia. Five children were 7 months of age or less; the other three were 3 1/2, 8, and 12 years old. This includes three operations for hepatoblastoma, three for hepatoma, and two for mesenchymal hamartoma. There were three right lobectomies, two trisegmentectomies, two extended left lobectomies, and one standard left lobectomy. With the use of this method, operative blood loss has been greatly reduced and operating technique significantly improved. After abdominal exploration and initial liver mobilization, whole blood is removed from the patient and simultaneously replaced with three times the volume of Ringer's lactate solution to maintain adequate intravascular volume. After the major blood loss has ceased, the patient is reinfused with his own blood and a simultaneous diuresis is induced with LASIX to remove the previously administered crystalloid solution. Metabolic demand is reduced by allowing the patient's temperature to drift down to 32 degrees C. Blood loss is further reduced by a Halothane-induced hypotension to a mean arterial pressure of 40 to 50 torr. The diluted blood lost during surgery has a low red blood cell volume per cc; therefore, each cc of blood lost depletes the total red cell volume by a lesser amount. This results in a nearly bloodless operative field which facilitates the ease, speed, and safety of the dissection. Use of this technique can avoid the need for massive intra-operative transfusions and the threat of cardiac arrest due to extensive blood loss during major liver resection in children.(ABSTRACT TRUNCATED AT 250 WORDS)