There were investigated 583 cases with tumors of the urinary bladder and 612 patients with non-malignant diseases of the urinary tract. Samples of voided urine were taken from all cases and direct smears fixed by drying were stained by rapid blue polychrome-tanin Drăgan method Cytological results were compared with endoscopical and pathological findings. The overall rate of real positive results was 91.7% and false negative results were noticed in 8.3% of cases. A direct relationship between real positive results and histological "G" was found. Causes for false negative results were: tumor developed in a bladder diverticulum, calcified tumor, irradiated tumor, insufficient quantity of voided urine, chronic urinary infections and underestimation of cytological criteria of cellular malignancy. There were 9 false positive results in patients with nonmalignant diseases, due to lithiasis, chronic renal failure and chronic urinary infections. The cytological grade of differentiation was performed by the method purposed by Friedman and Ash, and concordance with the standard histological finding was 76.4%. Urine cytology is thought to be a useful method in the primary diagnosis and recurrences of transitional cell carcinoma of the urinary bladder, in all patients with hematuria, recurrent infections of the urinary tract and neglected lithiasis.