The article describes a patient with primary, closed, calcified renal cyst in whom the first symptoms appeared three years ago. They were manifested as a dull pain in the flank spinal region. A hard painless tumour, of the size of a man's hand, with clearly limited contours, without signs of fluctuation, was palpable in the left paraumbilical region. The intravenous urography revealed the existence of the pyelocaliceal system of the left kidney displaced by a cranially large cyst. The finding was confirmed by ultrasound. Computerized tomography revealed a cyst of 120 x 85 x 70 cm of size. Its wall was calcified and the content liquidus. Renovasography was performed after constatation that renal echinococcus was in question. This procedure enabled a good insight into the distribution of the blood vessels. On the basis of this finding resection of the lower part of the left cystic kidney was performed. The postoperative course was normal. The histologic finding was: Echinococcus cysticus.