A total of 481 serum samples was collected from asymptomatic carriers of HBsAg as well as some patients with acute and chronic hepatitis, type B. The sera were obtained mainly from blood banks in the following countries; Poland, Hungary, Romania, Bulgaria, Yugoslavia, and the European part of the Soviet Union. Asymptomatic carriers of HBsAg from Poland and Hungary showed a preponderance of adw subtype over ayw subtype (Poland -80.7% adw, Hungary -72.2% adw). Carriers from the remaining countries showed the reverse situation: Bulgaria -71.5% ayw, Yugoslavia -79.0% ayw, Romania -82.8% ayw, Soviet Union -87.5% ayw. No individuals were found among these indigenous populations to have the adr or ayr subtypes but two carriers appeared to have the unusual subtype adyw.