Patients treated at the Urological Clinic in Hradec Králové on account of carcinoma of the kidney are systematically followed up since 1962. In the submitted paper the authors evaluate patients treated during 1985-1991. During the mentioned period at the Urological Clinic in Hradec Králové 365 patients with carcinoma of the kidney were treated. In 55 (15%) invasion into the renal or inferior vena cava was proved (in 43 men and 12 women). In 38 patients the tumour with a thrombus of the inferior vena cava was on the right side, in 17 a tumour of the left kidney was removed. The right to left ratio is 2.2:1. Surgery of tumourous thrombosis depends on the level of the upper margin of the tumourous thrombus. A tumourous thrombus in the subhepatic part of the inferior vena cava can be treated either by massaging into the renal vein after obliteration of the artery or by parietal resection of the inferior vena cava. In 18 patients the authors were able to remove the thrombus by massaging into the renal vein. In 32 patients the inferior vena cava was resected. In five the tumourous invasion was not resolved, either because of extensive secondaries (in the liver and lungs) or because of direct tumourous infiltration of the wall of the inferior vena cava.(ABSTRACT TRUNCATED AT 250 WORDS)