Nuclear eosinophilic inclusions due to excess HBcAg [hepatitis B core antigen] particles were identified in cases of [human] chronic hepatitis B virus infection. As the euchromatin space of affected nuclei is sanded by numerous core particles with concomitant dissolution of the chromatin network, spiky, finely granular and eosinophilic inclusions without a limiting membrane become visible in hematoxylin and eosin-stained paraffin sections. These HBcAg inclusions stain greyish pink with chromotrope aniline blue and are negative for orcein, the periodic acid-Schiff reaction and the Feulgen reaction for DNA. Sanded nuclei were detected, although not always and only few in number, exclusively in HBAg-positive patients when a focal (as in chronic aggressive hepatitis) or a generalized core cormation (as in immunosuppressed kidney transplant recipients) could be demonstrated by EM or immunofluorescence. The positive finding of sanded nuclei in a persistent hepatitis B virus infection apparently indicates an excessive core formation the extent of which should be verified by specific methods.