Intravenous heroin abusers comprise a high risk group for hepatitis B and C viruses (HBV and HCV) infection. Chronic alcoholics with liver disease (LD) also comprise a high risk group for HBV infection whereas the frequency of antibodies to HCV (anti-HCV) ranges from 27-42.6%. In this study, HBV and HCV infection markers were determined in alcoholic patients with (83 patients) or without LD (68 patients) in order to assess the prevalence of these markers (HBsAg, HBsAb, HBcAb and anti-HCV). The reason for the study was a lack of established data in this group of patients in Greece. The disease control groups consisted of 70 non-alcoholic hospitalized patients and 60 heroin addicts, whereas 1342 healthy blood donors were also investigated. Our results showed significantly increased prevalence of HBV infection markers in chronic alcoholic patients compared to healthy controls and non-alcoholic hospitalized patients. The findings were independent of the presence or absence of LD. In contrast to heroin addicts, where anti-HCV antibodies were observed in 90%, there was no difference in the prevalence of anti-HCV antibodies in chronic alcoholics (with or without LD), nonalcoholic hospitalized patients or healthy controls. In conclusion, we found that in this area of north-western Greece, chronic alcoholics, independent of the presence of LD, comprise a high risk group for HBV infection but very rarely have HCV infection. The latter finding may reflect technical or socio-economic differences regarding the lifestyle of our patients, and our population in general.