After auxiliary liver transplantation in the rat, partial liver grafts (30% of the liver) were perfused with mesentericosplenic venous blood. This means a decrease in the total liver blood flow by approximately 34%. Recipient livers retained their arterial and pancreaticoduodenal inflow. Surgical interventions were carried out on the recipient's liver to evaluate the effect of the varying induced functional handicap on the fate of the graft in association with a decreased liver blood flow. Graft survival was obtained in all groups, but the conditions of the graft varied inversely with the severity of the functional handicap of the recipient's liver. Compared to previous experiments in which the auxiliary grafts were supplied with total portal blood inflow in the same experimental model, the grafts in this study showed a slightly impaired increase in weight. This impairment was attributed to the decreased blood flow. Recipient livers deteriorated or just maintained their size, even after 70% hepatectomy, despite the pancreaticoduodenal venous and arterial inflow. These results suggest that the total liver blood flow in combination with the functional state of the remaining recipient liver, rather than the quality of venous blood deriving from certain splanchnic areas and/or peculiar factor convoyed with it, determines the survival of a liver graft.