Immunohistochemical evaluation of localization of matrix metalloproteinase-9 (MMP-9) and an inhibitor of matrix metalloproteinase-1 (TIMP-1) and cell proliferative activity in the production Ki-67 protein in benign prostatic hyperplasia (BPH), and adenocarcinoma with different Gleason scores was performed. Moderate positive correlation between the Gleason scores and cell proliferation index usind Ki-67 antigen (rs = 0.674), moderate negative correlation between Gleason scores and levels of MMP-9 production (rs = -0.660), and weak significant negative correlation between the levels of cell proliferative activity and MMP-9 production by tumor cells (rs = -0.369) were established. Invasive properties of tumor cells, expressed in the destruction of type IV collagen in basement membrane and connective tissue of the stroma of the prostate, are associated with imbalance in MMP-9 protein, and blocking enzyme, TIMP-1; and TIMP-1 production is reduced significantly in adenocarcinomas with different Gleason scores compared with BPH.