The aim of the study was to assess the prevalence of anti-extractable nuclear antigen (ENA) antibodies in patients with chronic HCV infection. We studied 69 consecutive patients with chronic hepatitis C, 59 control subjects with non-HCV liver diseases, and 22 control subjects with extrahepatic, non-immune-mediated, chronic diseases. Thirty-two (46.3%) of 69 patients with HCV infection had anti-ENA antibodies: 16 (23.1%) showed anti-SSA antibodies and 14 (20.2%) had anti-SSB antibodies. Four of the patients with HCV infection suffered from sicca syndrome and three of them had also anti ENA antibodies. The prevalence of anti-ENA antibodies was significantly higher in the anti-HCV subjects compared with both control groups. Twenty-six of 44 HCV-antibodies-positive females had anti-ENA antibodies, compared with 6 of 25 males, showing a sex related difference. In conclusion, our results outline a specific role of HCV infection in the induction of anti-ENA antibodies. Female sex seems a predisposing condition.