The presence of low level hepatitis B virus (HBV) and hepatitis C virus (HCV) infections was assessed in serum from 67 hepatitis B surface antigen (HBsAg) negative alcoholics from France without previous blood transfusions and/or i.v. drug abuse. It was found that 19 (28%) of this alcoholic population had past exposure to HBV as shown by the presence of antibodies to the surface (anti-HBs), core (anti-HBc) and e (anti-HBe) antigens. Two patients (3%) had low level circulating encapsidated HBV as determined by the highly sensitive capture PCR technique. Previous exposure to HCV was assessed by three serological tests: the first generation ELISA (C-100-3), a second generation recombinant immunoblot assay (RIBA II) and a radioimmunoassay based on highly conserved HCV core peptide sequences; 7 (10.5%) were found to be reactive in at least two serological tests. Among 64 serum samples available for RNA PCR testing, 6 were found to be HCV RNA positive (9.4%). Taken together, 8 (13%) of this alcoholic population were positive for HCV by RNA PCR and/or at least two serological tests. We conclude, that even in the absence of known risk factors and HBsAg negativity, patients with alcoholic liver disease have a significantly higher prevalence of markers of past or ongoing HBV or HCV infection than healthy individuals.