This study aimed to determine the prevalence of nonalcoholic steatohepatitis in Thai patients with non-HBV, non-HCV chronic hepatitis. The clinical and laboratory findings associated with non alcoholic steatohepatitis were discussed. Forty-six patients with negative markers for viral hepatitis B and viral hepatitis C and no history of alcohol consumption or consumption less than 20 grams of ethanol per day were recruited. The informed consent for liver biopsy and blood collecting to identify the etiology of chronic hepatitis was performed. Most patients (76.1%) exhibited fatty metamorphosis of the liver which included steatosis (21.8%) as well as steatohepatitis (54.3%). Eleven of 46 patients (23.9%) were classified as cryptogenic chronic hepatitis. There were statistically significant differences between the fatty metamorphosis group and the cryptogenic chronic hepatitis group with regard to the fasting blood sugar, serum alkaline phosphatase, serum ferritin and histologically necroinflammatory grading score (p < 0.05). Between the steatosis group and the steatohe-patitis group, body mass index (BMI) was the only factor showing statistically significant difference (p = 0.02). Eight from 25 NASH-patients had diabetes mellitus (32.0%) and the AST to ALT ratio in this group was 0.6. The histopathological assessment for inflammation and fibrosis by using Knodell score, the fibrosis score which equal or
higher than 3 was found in 20.0% of NASH- patients.
Conclusion: The prevalence of NASH-patients In Thai patients,with non HBV, non HCV chronic hepatitis was 76.1%,while the liver biopsy can add the diagnostic yield especially in the group of unexplained chronic hepatitis with obesity, diabetes mellitus and dyslipidemia.

Keywords: Prevalence, Nonalcoholic steatohepatitis, Chronic Hepatitis