We measured plasma levels of fibrinogen degradation products (FgDP) with newly developed enzyme-linked immunosorbent assay based on monoclonal antibody to assess the fibrinogenolytic state in 52 patients with various liver diseases (27 patients with liver cirrhosis, 10 with chronic hepatitis, 7 with acute hepatitis, 6 with hepatocellular carcinoma, 2 with intrahepatic cholestasis). As compared with 20 healthy subjects (upper limit: 580 ng/ml), elevated plasma levels (660-32000 ng/ml) of FgDP were found in 19 (36.5%) patients. When analyzed according to the underlying disease categories, the magnitude of elevations of FgDP were most prominent in patients with chronic hepatitis. No correlation was found between plasma FgDP levels and serum AST or ALT activity. These findings indicate that increased primary fibrinogenolysis is not rare in liver disease, but poorly correlates with liver function.