The rarity of such form of nephroblastoma containing about 4% among embryonal renal tumors in this paper, was the subject of special attention. The necessity of preoperative differential diagnosis particularly in cases of congenital multicystic kidney, congenital hydronephrosis and retroperitoneal sympathetic neoplasms was stressed. Radiological investigation facilitate distinguishing of the three pathological forms. A multicystic degeneration of kidney is usually bilateral and it includes both the medulla and the renal cortex. The cystic patterns nearly equal in size are multiple and minute. In the bilateral Wilms' tumour besides the kidney enlargement there are deformations such as hydrocalyx , hydronephrosis or modeling signs. In case of congenital hydronephrosis the kidney keeps the same size and produces the thinner cortex zone. The neoplasms of the sympathetic nerve origin produce first the displacement of kidney and then the deformation of pelvico -calyceal system with modeling signs and sometimes with hydronephrosis. In the above mentioned entities, late urographical pictures are of great significance. The angiographic investigations of kidney play a very important part in the differential diagnosis and planning of operative procedures. The nephrographic phase of angiography shows the quantity and location of active renal parenchyma. A renal arteriography is also important in the evaluation of the applied therapy, particularly in case of multistage therapeutic procedures.