Background. Except for smoking and certain occupational exposures, the etiology of bladder cancer is largely unknown. Several case reports have described familial aggregation of transitional cell carcinoma of the bladder. Although the majority of patients with bladder cancer do not have family history of transitional cell carcinoma of the urinary tract, the study of familial transitional cell carcinoma may lead to the knowledge on the pathogenesis of this disease. The purpose of this study was to describe three cases of urinary bladder cancer in a single three-member family, i.e. in two generations (mother and son) and a family member related by marriage (the patient’s wife). Case report. Three cases of urinary bladder cancer occurred in a three-member family within the interval of 5 years. The following common characteristics were detected in our patients: old age (over 60), working as farmers for more than 50 years, negative personal medical history on relevant health disorders, place of birth - village, place of residence - village, the same water supply, similar nutrition, positive family history on urinary bladder cancer or other malignant tumors, the first sign of illness was macroscopic hematuria in all the patients and the same pathohistological type of cancer - carcinoma papillare transitiocellulare. Conclusion. The stated common characteristics in our cases indicate, above all, the impact of exposure to external surrounding factors on the occurrence of urinary bladder cancer.