The aim of the study was to assess the prognostic role of CD4 and CD8 expression and the type, density, localization and distribution of tumor infiltrating lymphocytes (TILs) in patients with breast cancer. Tissue samples were obtained from 88 breast cancer patients with operable disease and ductal histology. Forty-three women had pathologically confirmed axillary lymph node involvement. The TILs and expression of CD8 (cytotoxic T-cells) and CD4 (T-helper cells) were evaluated in the tumor samples using mouse monoclonal antibodies. Thirteen patients relapsed; nine of them had strong expression of CD4 and CD8, which was statistically significant. The patients with high expression of CD4 or CD8 had distinctly worse cancer specific overall survival (OS). High correlations between CD4 and CD8 expression and lymph node status and intensity of lymphatic infiltrate as well as between both markers were found. The analysis of tumor-infiltrating immune cells may be a valuable prognostic tool and a marker of lymph node involvement.