Hepatitis B virus (HBV) and hepatitis C virus (HCV) are hepatotropic and lymphotropic viruses endemic to Sicily. To evaluate whether these viruses may chronically infect patients with non-Hodgkin's lymphoma (NHL) and without liver disease, we examined serum samples from 24 such patients. Five cases (20.8%) revealed HCV infection, as shown by the detection of viral RNA through the polymerase chain reaction technique, while HBV-DNA was not found in any of them by the same method. These results provide one more epidemiological element supporting the hypothesis that the association between HCV infection and lymphoproliferative diseases is not a casual event, and show that HCV may chronically infect patients with NHL without producing liver damage.