The aim of our study was to evaluate the role of CD20 and CD45.Ro antibodies in acne and seborrheic dermatitis. A number of 20 patients with papular, pustular or nodular acne and another 20 patients with seborrheic dermatitis were available for our study. We removed bioptic material from all of them and we perform histochemical and immunohistochemical processing within the Laboratory of Histology, Histopathology and Immunohistochemistry of the University of Medicine and Pharmacy of Craiova. In acne, we could reveal a positive CD45.Ro immunomarking in rare lymphoid cells situated in the middle derma at a distance from the affected pilosebaceous follicle and in the inflammatory infiltrate subepidermically, and also a negative immunomarking in the inflammatory cells from the proximity of the affected pilosebaceous follicle. In patients with seborrheic dermatitis we noticed a positive immunomarking infiltrate of the papillary derma and a positive immunomarking of membrane for CD45.Ro in many lymphoid cells of the inflammatory infiltrate situated in the papillary derma predominantly disposed perivasculary. Conclusions. The absence of the cells marked with CD45.Ro in the proximity of the pilosebaceous follicle interested in acne excludes the direct participation of B- and T-lymphocytes in the perifollicular inflammatory process, though the T-lymphocytes can be revealed in a small number at a distance from the affected follicle. The inflammatory infiltrate from the seborrheic dermatitis proved to be rich in positive CD45.Ro cells and poorer in positive CD20 cells.