Activities of organelle specific enzymes (succinate dehydrogenase, glucose-6-phosphatase, acidic DNAase, acidic RNAase, acidic and alkaline phosphatases) were measured in homogenates and subcellular fractions of liver tissue of patients with cholelithic disease. Liver tissue samples analyzed were investigated also by light and electron microscopy. The data obtained were considered in connection with localization of cholelith in biliary system, type of inflammation, presence of subhepatic cholestasis and of accompanying syndrome of pancreatitis. Typical alterations were observed in the activity of organelle specific enzymes and in the ultrastructure of mitochindria, lysosomes and endoplasmic reticulum in cholelithic disease. The most distinct alterations in the enzymatic activities were found in choledocholithiasis as well as in subhepatic jaundice.