Histological changes which appear as a result of reperfusion injury of cold-preserved rat liver were studied at intervals of 0 hr, 3 hr, 24 hr and 48 hr of cold storage. The isolated livers were stored in a UW solution (University of Wisconsin), which is used in human liver transplantations. Computer image analysis of light microscopic sections (methyl green-pyronin stained) was used for the study and quantification of injured cells. The method of TUNEL was performed to prove possible apoptosis of sinusoidal endothelial cells and heptocytes. Bile production during reperfusion and ALT, AST, LDH and ACP were measured in the reperfusion medium at the end of the 90 min reperfusion. It has been confirmed that prolongation of the cold storage of liver results in extensive changes in the liver structure and increased injury of liver cells. Sinusoidal endothelial cells were damaged more and earlier than hepatocytes. It has been shown that methyl green-pyronin stained sections are advantageous for the study of these morphological changes, allowing the strongest view of these changes. The appearance of TUNEL positive cells and an increase in the levels of biochemical parameters, e.g. AST or ALT, indicate earlier cell injury. The methodology described in this article can be used for the study of reperfusion injury of the liver and for the study of this phenomenon in other experiments.