At the Urological Department in Hradec Králové the authors operated in 1989-1993 287 patients with renal tumours, in 45 of them a conservative procedure was used (15.6%). The group comprises 29 men and 16 women, mean age 56.5 years. The contralateral kidney was normal in 29 patients (64%), in 5 patients nephrectomy was performed on account of carcinoma and in 9 patients (20%) the second kidney was hypofunctional (hydronephrosis, cysts). In two patients a conservative procedure was used on account of malignity of the blood. In 33 patients the tumour was enucleated (73.3%), in 12 the upper or lower pole of the kidney was resected. In 6 patients the tumour was in the first clinical stage, but in four already in T 3a (imperative indication). Twenty-seven tumours were evaluated by the histologist as medium differentiated, 2 of 35 as poorly differentiated. Thirty-five tumours were carcinomas (77.7%), 8 were adenomas, one was angiomyolipoma and in one instance the scar after PEC was removed which was not reliably diagnosed before surgery. The preoperative examination comprised also immunological examination which, however, was not made in two patients. The immunologist evaluated the criteria as favourable in 21 patients (60%), as risky in 12, incl. 6 were immunotherapy was administered. One patient developed a urinous fistula which healed on a stent. During the investigation period no local relapse was observed.