OBJECTIVES. The aim of the present study was to determine the presence of the immune cells in the non-muscle invasive bladder cancer specimens of the patients divided according to clinicopathological characteristics and subsequent correlation of the results with before mentioned characteristics. PATIENTS AND METHODS. Tumor specimens from 115 patients with solitary papillary non-muscle invasive bladder cancer were retrieved and tissue microarrays were constructed. The patients were divided in two groups: patients who developed recurrent disease and patients without recurrence. Immunhistochemical staining with anti-CD3, CD4, CD8, CD20, CD56, CD68 and GrB was performed. Quantification of the positive cells was done automatically using software – «Spot Browser 2.3.3», Alphelys. RESULTS. Statistically significant difference between distinct cell-lines in recurrent and non-recurrent group of patients was determined for CD3+ and CD8+ cells. Statistically significant difference between distinct cell-lines in patients grouped according to tumor diameter and tumor stage was determined for CD56+ and CD68+ cells separately. The ratio between different subpopulations of T lymphocytes was determined, and the ratio between CD4+ / CD8+ and GrB+ / CD8+ cells demonstrated statistically significant difference between non-recurrent and recurrent group of patients. Logistic regression analysis of the markers used in the study showed high prognostic value and statistical significance of the model; univariate and multivariate analysis revealed statistical significance of the CD3+ and CD8+ cells on recurrence prediction. Cox regression analysis demonstrated that elevated levels of CD4+ cell infiltration increase the risk from recurrence ( e.g. shortens recurrence-free survival ), whereas elevated levels of the CD8+ infiltration decrease the risk from recurrence ( e.g. prolongs recurrence-free survival ). VII CONCLUSION. The results of our study show the potential in the clinical use of immune cells analysis as possible prognostic factors of bladder cancer natural history.