AIM OF RESEARCH: to evaluate glomerular filtration rate dynamics before and after the various options and volume of surgery in patients with kidney malignant neoplasms. PATIENTS AND METHODS: We examined 62 patients (men – 41, women - 21) surgically operated with malignant renal tumors (open, laparoscopic, or robot–assisted total nephrectomy or partial nephrectomy). The group 1 (n = 28) – tumor resection, group 2 (n = 34) – nephrectomy. Estimated glomerular filtration rate (eGFR) was calculated by several methods: a brief MDRD formula [7], D.W. Cocroft and M.H. Gault formula (CCG) [8], the equations of CKD-EPI [9] and MCQ. RESULTS: showed that surgical operation led to authentic increase of SCr and Sur and significant decrease of eGFR regardless of the extent of surgical intervention. Intergroup differences in all researched parameters after surgery has not been established, although there was a trend downwards concerning all used eGFR methods in patients with nephrectomy (not statistically significant due to the considerable scatter of data). CONCLUSION: Surgical interventions in patients with renal cancer in the great majority of cases induce the development of chronic kidney disease 2–3 and, even 4 stages – an independent predictor of cardiovascular morbidity and mortality.