Surgical resection remains the mainstay of treatment for patients with hepatic tumors, despite the asso-ciated morbidity including the need for blood transfusion. Acute isovolemic hemodilution (AIH) has been shown to decrease the transfusion requirement for cardiac, urologic, and orthopedic procedures. However, the reported experience with AIH during hepatic resections is limited. Seven patients underwent major hepatic resection from July 1992 to June 1994 with standard AIH. Their clinical parameters were compared with those of nine matched control patients during the same time period. AIH and control patients had similar preoperative laboratory values (hematocrit, bilirubin, and coagulation studies), extent of liver resection, and pathologic diagnoses. Mean tumor diameters were larger in the AIH group (9.3 cm vs. 5.8 cm). Most important, patients managed with AIH required homologous blood transfusions significantly less often than the control group (14% vs. 67%; P = 0.05). Furthermore, if they did receive transfusions, AIH patients needed fewer units of red cells (0.1 ± 0.1 units vs. 1.7 ± 0.6 units). There was no morbidity associated with AIH. AIH can be safely performed in patients undergoing major hepatic resection for malignancy. AIH appears to reduce the number of patients requiring homologous blood transfusion as well as the number of units transfused per patient. This technique warrants further study in a larger prospective, randomized trial.