To comparatively analyze the morphological and immunophenotypic parameters of urothelial carcinomas of the renal pelvis and bladder. Surgical specimens from 196 patients diagnosed with urothelial carcinoma of the renal pelvis and bladder were investigated. Paraffin sections were immunohistochemically examined using the standard protocol. Antibodies against CK5/6, CD138, CDX2 ('Dako'), CK7, CK14, CK20, CEA, CD10, CD117, EMA, E-Cadherin, HMWCK, p63, Uroplakin III, Vimentin ('Novocastra'), CD44, GATA-3, MUC1, MUC2, and MUC-5AC ('Cell Marque') were used. Most tumors (n=147 (75%)) were invasive. Of them, 65 (33%) cases had a histological structure of conventional urothelial cancer; and 3 (1.5%) had paradoxical differentiation. Divergent tumor zones were verified in 66 (34%) neoplasms; 4 (2%) cases showed an inverted growth pattern. Pseudosarcomatous stroma reaction in the invasion zones was verified in 9 (5%) cases. The tumor stage corresponded to pT2-pT4 in 128 (65%) tumors. Urothelial carcinomas of the renal pelvis and bladder show a broad spectrum of histological variants. The findings support that, unlike urothelial carcinomas of the bladder, the majority of primary urothelial carcinomas of the renal pelvis are high-grade and highly invasive.