ABSTRACT— Factors influencing the preservation of HBcAg in formalin‐fixed, paraffin‐embedded liver tissue have been analysed. Fixation time, choice of the embedding medium, deparaffinization and selection of anti‐HBc proved to be critical variables. For optimal results, fixation in 4% buffered formalin for no longer than 24–48 h, the use of wax with a low melting point, a heating step prior to deparaffinization, and a search for anti‐HBc specifically reactive for paraffinated HBcAg are recommended.