The effect of long-term administration of the novel maleimide derivative with antiproliferative activity on kidney morpho-functional state in experimental (1,2-dimethylhydrazine-in-duced) colon carcinogenesis has been investigated on 60 male rats. 1,2-Dimethylhydrazine was injected subcutaneously in dose 20 mg/kg one time per week during 20 weeks. Maleimide derivative in dose of 0,027 and 2,7 mg/kg was given per os daily during the same time. The state of kidneys was evaluated after morphometrical investigation and measurement of urea, creatinine and chlorides levels in blood serum. It hasn’t been revealed significant structure-functional changes in kidneys after daily administration during 20 weeks. The induction of proliferate activity of distal tubules epithelial cells and reducing of epithelial layer thickness in proximal tubules in kidneys in rats with experimental carcinogenesis has been observed. In experimental colon carcinogenesis, maleimide derivative dis­plays some protective action to tubular apparatus of rat’s kidney cortical nephrons and reduces the frequency of preneoplastic changes in tubules epithelial cells.