Nonalcoholic fatty liver disease (NAFLD) encompasses a histological spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) that may progress eventually to cirrhosis. Any clinically useful serum biomarkers have never been reported to distinguish patients with NASH from those with simple steatosis. The serum CRP concentration, formerly used as a marker of acute-phase reaction, has been revealed to be a strong predictor of coronary event after the introduction of the high-sensitivity assay method. Patients with metabolic syndrome also have been reported to have higher high-sensitivity CRP(hs-CRP) concentration. We showed patients with more active form of NASH (grade2-3) have higher concentration of hs-CRP than those with quiescent form of NASH (grade1) or simple steatosis. hs-CRP may be a promising biomarker for screening of NASH, a hepatic manifestation of metabolic syndrome.