Using immunohistochemical and morphometric methods, the quantitative composition and structural localization of immunocompetent cells were studied in human spleen (n=20, autopsy material). The detailed morpho-functional characteristics of splenic white and red pulp are presented. Cell subpopulations of T (CD3+, CD4+, CD8+) and B lymphocytes (CD20+), natural killer cells (CD57+), tissue macrophages (CD68+) and dendritic cells (CD35+, S100+) were studied. An analysis of the correlations of immunocompetent cells in different regions of white and red pulp may become the basis for optimization of histopathological diagnosis definition in clinical practice