This study illustrates the relationship between the hepatitis B virus (HBV) carrier state and primary hepatocellular carcinoma in a large family of Maori (173 members) amongst whom four brothers have died of primary hepatocellular carcinoma. The brothers were from a generation of fourteen siblings, eleven of whom were tested for hepatitis B surface antigen (HBsAg) and all found to be positive. Amongst the offspring of this generation there were 13 HBsAg positives from 28 children (46%) born to female carriers but no HBsAg positives amongst the 28 offspring of male carriers. The study provides further evidence that the morbidity which often follows HBsAg carriage, may be associated with early (perinatal) infection. There was a marked decrease in HBV serologic markers in succeeding generations, from 100% in generation two, to 55% in generation three and 14% in generation four, unrelated to the use of hepatitis B vaccine.