In the retrospective investigation we estimated the CEA levels in urine and urine cytology in 293 patients with urinary bladder cancer (group I) and in 129 patients with urinary tract infection (group II). An increased CEA level was found in 212 cases of bladder cancer and in 109 cases of urinary infection. Neoplastic cells in urine sediment were identified in 254 cases in the first group, while in the second, multiple inflammatory cells and pyuria were diagnosed in 55 and 56 cases, respectively. The combined examination (increased CEA level and/or positive cytology of the urine sediment) allowed for the diagnosis of neoplastic disease in 270 patients in the first group and infection diseases in 123 patients in the second group. After surgical therapy an increased urine CEA level and neoplastic cells in the urine cytology were found in 1 case which was then confirmed histopathologically. In the group with urinary infection an increased CEA level in urine, after antiphlogistic therapy, was found in 5 cases, inflammatory cells in 12 cases, pyuria in 8 cases and suspect cells were found in 6 cases in the group with urinary infection. In specimens from these cases, after electroresection, bladder cancer was diagnosed in 2, and cystitis cystica type changes in 2 cases.