A sero-prevalence study of antibodies against the hepatitis A and B virus is described along with the prevalence of the surface antigen of the hepatitis B virus (HBs1 Ag). Two groups are compared: the first comprising young adults born between 1961 and 1968; the second, an older population aged 50 and above. Results show that only 3.9% of the younger population were found to have antibodies against the hepatitis A virus, in sharp contrast to the older generation in whom the prevalence of antibodies was as high as 40.3%. There is a prevalence of 0.4% of HBs Ag in the younger group, while the rate in the older population is 1.5%. Only 7.1% of the younger group were found to have antibody markers for anti-HBc2 and 3.5% for anti-HBs. In the older group the respective figures are 32.5% and 15.8%.