A community health survey of 923 residents aged 30 years or more was performed in Putai Township of Taiwan. To elucidate the relationships between hepatitis C virus (HCV) and surrogate tests for non-A, non-B hepatitis in hyperendemic areas of hepatitis B virus (HBV) serum levels of alanine aminotransferase (ALT), triglycerides, cholesterol, hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) were examined. Glucose tolerance tests and the history of diabetes treatment were used to define the diabetes status. Fatty liver was diagnosed by sonography. The prevalence of anti-HCV was 2.6% (95% confidence interval, 1.6-3.6%). Elevated ALT and fatty liver were significantly associated with anti-HCV in univariate analysis. Anti-HCV was not an associated factor for fatty liver after adjusting for serum triglycerides and cholesterol, sex, body mass index and diabetes status through multiple logistic regression. However elevated ALT was still associated with anti-HCV after adjusting for serum triglycerides, sex, body mass index, HBsAg and age through multiple linear regression. The anti-HCV prevalence was similar between HBsAg-positive and negative subjects. Aggregation of HCV infection was found among spouses. It was concluded that elevated ALT and intimate contact with HCV carriers might be associated factors for HCV infection, and that HBV infection and fatty liver were not related to HCV infection in Taiwan.