In 1973, epidemiologic and serologic data related to hepatitis B infection were collected from the residents of two remote Alaskan Eskimo villages located in an area of high hepatitis incidence. A total of 418 sera were tested by solid-phase radioimmunoassay for heaptitis B surface antigen (HBsAg) and antibody to that antigen (anti-HBs). The overall infection prevalence of 54.8% in the two villages included a 13.9% prevalence of HBsAg and a 40.9% prevalence of anti-HBs. Families containing an individual with HBsAg had significantly higher infection prevalence than those without an antigen carrier. Larger households had higher proportions of infected members than smaller households. The data suggest that efficient transmission of hepatitis B virus occurs within the household setting in these villages by other than classically established parenteral routes.