Platelet-activating factor (PAF) may play an important role in graft injury in liver transplantation. Livers excised from male Wistar rats were preserved in University of Wisconsin solution for 6 h and then perfused with Krebs-Henseleit solution containing vehicle (bovine serum albumin) or PAF. Impairment of parenchymal cells was assessed by reference to tissue adenosine triphosphate levels, oxygen consumption and alanine aminotransferase activity in the effluent. The effect on non-parenchymal cells was evaluated by measurement of purine nucleoside phosphorylase and alanine aminotransferase levels in the effluent. Administration of as little as 1.0 ng kg-1 PAF caused a significant decrease in adenosine 5'-triphosphate concentration and oxygen consumption (P < 0.05), although non-parenchymal cell injury was not affected. PAF can therefore cause liver graft dysfunction with hepatocytes as the main target, even in the absence of microcirculatory disturbance secondary to interaction between blood cells and endothelial cells.