Although livers can be successfully preserved for 24 hr or more, often the transplanted livers have poor or no (primary nonfunction) function. The quality of the liver does not appear dependent upon the time of preservation but may be dependent upon the condition of the donor. In this study we have investigated the effects of fasting on the quality of livers for transplantation. Rabbits were fasted (48 hr) and livers preserved in the UW solution for 6–8 hr. Functions of the liver were analyzed by isolated perfusion for 2 hr. Also, pigs were fasted for 72 hr, livers preserved for 12 hr, and viability determined by orthotopic transplantation. Fasting depleted the liver glycogen by 85% but had no effect on ATP or glutathione concentrations. Rabbit livers from fasted animals produced similar amounts of bile, released similar concentrations of lactate dehydrogenase (LDH) and aspartate amino transaminase (AST) into the perfusate, maintained similar concentrations of ATP and glutathione in the tissue, and had a similar intracellular K:Na ratio after 24-hr preservation when compared to livers from fed animals. After 48-hr preservation, livers from fasted animals were less viable than livers from fed animals, including: reduced bile production (2.0±0.3 vs. 5.0±0.9 ml/2 hr, 100 g), greater release of LDH (3701±562 units vs. 1123±98 units) and AST, less ATP (0.326±74 vs. 0.802±160 nmol/g), less glutathione (0.303±13 vs. 0.933±137 nmol/g), and a lower K:Na ratio (1.5±0.9 vs. 7.4±0.6). Pigs receiving livers from fed animals preserved for 12 hr had better survival (5/6, 83%) than livers from fasted animals (3/6, 50%). The results show that the nutritional status of the donor can affect the outcome of liver preservation and transplantation. Increased injury in livers from fasted animals may be due to the loss of glycogen that may be an essential source of energy in the initial posttransplant period. In clinical liver transplantation the nutritional status of the donor may be an important factor in the initial function of the liver, and methods to increase the nutritional status of the donor may be important in increasing the quality of livers.