Electron-microscopical exammination of a liver biopsy from a young female drug addict with clinically relapsing serum hepatitis revealed virus-like particles free in the liver cell cytoplasm. In addition, there was intracellular cholestasis, and numerous clefts were found in the cytoplasm of hepatocytes, presumably caused by the presence of cholesterol crystals which were dissolved during the processing of the tissue. Such clefts have earlier been reported in liver cells in patients with cholestasis and hypercholesterolemia, but not in patients with viral hepatitis and a normal serum cholesterol concentration.