We have investigated and treated 54 patients (44 men and 10 women) with the mean age of 64.6±9.93 years (range 38-90) from the emergency admissions due to macrohematuria. All patients were investigated in the standard manner with additional blood analysis (IFA) regarding IgG and IgM of Herpes simplex viruses (HSV) types 1 and 2, cytomegalovirus (CMV) and EpsteinBarr virus (EBV). Urine and tumor PCR were also done to detect these viruses. Urethral swab was tested for human papillomavirus (HPV) of high carcinogenic risk. T1NxM0 bladder cancer was diagnosed in 61% of cases (n=33), T2NxM0 – in 12 patients (22.2%), and 8 patients were diagnosed with locally-advanced disease. In one case papilloma was detected. Multiple tumors were diagnosed in 28 patients. Pathologically high grade urothelial cancer was detected in 72.2% of cases (n=39), low malignancy potential tumors were detected in 14 patients. Recurrence was evident in 15 patients. Those patients, who experienced recurrence and had high-grade carcinoma or locally advanced disease, presented with the increased level of antibodies IgG to CMV compared to localized tumors with low malignancy potential carcinomas. Antibody titer correlated with the level of the antibodies to other viruses, with the presence of the CMV virus and other viruses in the tumor tissue and with the tumor stage and recurrence. Other viruses and their antibodies were uncorrelated to the tumor characteristics. High grade tumors contained DNA of the HPV viruses of high carcinogenic risk.