Summary:Sera from 836 natives from the Sepik District of New Guinea were tested for Hepatitis B antigen and antibody by the passive haemagglutination technique and ABO grouped. Results show that not only was there no association between blood groups and Hepatitis B antigen carriers, but also that there was no relationship between blood groups and those susceptible to infection by the Hepatitis B antigen‐associated virus as estimated by the summation of antigen and antibody positives in the population studie