Upper Tract Urothelial Carcinoma (UTUC) is an uncommon disease which occurs more frequently in some regions of Balkan countries than in other areas in the world. Investigation of UTUC in the South Morava River basin and its tributaries where BEN is endemic revealed increased frequency not only of tumour of the renal pelvis and ureter but also of urinary bladder tumours. A comparative morphological and immunohistochemical study of UTUC in the BEN region and control rural and city populations free of BEN, identify growth pattern as the best morphological characteristic which differentiated BEN and control tumours, i.e. solid growth for BEN tumours and papillary for control tumours. Overexpression of tumour suppressor p53 as well as decreased expression of E-CD was detected in BEN tumours. Other cells cycle related molecular markers--Cyclin D1, p16, and HER-2 showed no difference in expression between groups, as well as the proliferative marker Ki-67. Investigation of apoptosis-related markers identifies Bax as a specific marker of BEN-associated UTUC. Decrease of the pro-apoptotic protein Bax together with alteration of Survivin may be indicative of specific disturbances of an intrinsic apoptotic pathway in UTUC arising in endemic areas.