OBJECTIVE prevalence of viral hepatitis (B and C) changes geographically. Our aim was to determinate the prevalence of hepatitis B (HBV) and hepatitis C virus (HCV) serological markers in healthy working population and to describe the epidemiological characteristics associated to its presence. METHODS blood samples and epidemiological data of 5,017 healthy workers from Murcia and Madrid were recorded prospectively. RESULTS a total of 5,017 healthy volunteers participated. Mean age 39 ± 11 years, men predominance (73 %). Prevalence of serological markers of HCV and HBV was 0.6 % and 0.7 %. Age of patients with HCV antibody was significantly higher (43 + or - 9 years vs. 39 + or - 11 years; p = 0.03). We observed significant differences in liver test values (alanine aminotransferase [ALT] 64 ± 56 IU/L vs. 28 ± 20 IU/L; p < 0.001; aspartate aminotransferase [AST] (51 + or - 45 IU/L vs. 23 + or - 12 IU/L; p < 0.001) and in gamma-glutamyltransferase(GGT) value (104 + or - 122 IU/L vs. 37 + or - 46 IU/L; p < 0.001. The presence of HCV antibody was related significantly to previous transfusion (13 % vs. 5 %; p = 0.03), tattoos (29 % vs. 13 %; p < 0.01), intravenous drug addiction (13 % vs. 0.2 %; p < 0.001) and coexistence with people with positive HCV antibody (16 % vs. 4 %; p < 0.001). In HBV no differences in basal characteristics were observed with exception in AST values (29 + or - 15 IU/L vs. 23 + or - 12 IU/L; p < 0.01). Hepatitis B surface antigen (HBsAg) was related significantly to previous transfusion (15 % vs. 5 %; p < 0.01), tattoos (26 % vs. 14 %; p = 0.04) and coexistence with people with positive HBsAg (17 % vs. 4 %; p < 0.001). CONCLUSIONS Prevalence of serological markers in healthy working population is low. Risk factors for infection were previous transfusion and tattoos. Intravenous drug addiction was only a risk factor in HCV.