The pathological picture of Marburg-virus disease was described and discussed in the previous papers. Despite the obviously pantropic nature of the virus, damage to the liver was prevalent; therefore the histological features of the accompanying hepatitis are worth investigating. By comparing the findings in inoculated guinea pigs, the autopsies of the patients in whom the disease was fatal and the results of biopsies from convalescent patients, it was possible to define the formal genesis and development of the liver damage and the subsequent recovery. The earliest alterations caused by the liver infection are of special interest, because obviously in advanced cases they may be masked by additional and unspecific changes.