The Nantong area is a high risk region for primary hepatocellular carcinoma (PHC) in the inshore area of the Yangtze River. However, no detailed data are available about hepatitis C virus (HCV) infection in this area. We examined the incidences of anti-HCV and HCV-RNA in blood donors with hepatitis B surface antigen (HBsAg)- and hepatitis B core antibody (HBcAb)-negative and patients with chronic liver diseases in the Nantong area at Nantong Medical College, Jiangsu Province, the People's Republic of China. The incidences of HBV markers (HBsAg and/or HBcAb), anti-HCV (C100-3), second generation anti-HCV, HCV-RNA and any marker of HCV in the Nantong area were found to be: 0.0, 0.7, 0.4, 0.2 and 0.7% in donor bloods; 16.9, 0.0, 3.4, 15.7 and 16.9% in patients with acute hepatitis; 82.8, 2.7, 4.8, 7.5 and 10.2% in those with chronic hepatitis; 86.4, 4.5, 9.1, 4.5 and 11.4% in those with liver cirrhosis; 87.5, 6.3, 0.0, 0.0 and 6.3% in those with PHC; and 21.8, 1.3, 1.3, 0.0 and 1.3% in patients without liver diseases, respectively. Although the Nantong area is a high risk region for PHC, these data suggest that HCV infection is not an important aetiological factor for PHC in this area.