Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a rare, recently described entity. The authors present three new cases. The histological picture was that of classic MTSCC, with alternating small tubules located in a mucin-containing stroma, and spindle cell areas composed of bland, monomorphic cells. On immunohistochemistry, the tumors were positive for epithelial markers, including CK7 and CK18, vimentin, CD15, AMACR, and neuroendocrine markers, such as NSE and CD57. On FISH analysis we found losses on chromosomes 1 and 8, and gains of chromosomes 7 and 17. This is the first report of this rare entity in Polish medical literature.