Studies on human brains with ischemic insult were performed with immunohistochemical methods to identify antigenic properties of cells participating in that pathology. The 10 patients of whom the brains were obtained at autopsy aged from 51 to 81 years had survived from 3 to 17 days from the onset of stroke to death. Cells involved in the process of decomposition of infarcted tissue were analysed with immunocytochemical methods and CD68, EMB11 (Dako) monoclonal antibody (MAB) was used. Three cell types were visualized e.g. macrophages, astrocytes and microglial cells. Cells identified were numerous in the boundary zone of infarcts and only rarely distributed in the surrounding tissue at a distance from the necrotic tissue. A few cells only were stained in the contralateral hemisphere and none were astrocytes. Our results provide evidence that morphologically different cell types can be marked with the same antibody, which may be in agreement with their similar function in the pathogenesis of ischemic brain stroke.