Aim. To analyze our own results of the course of early postoperative period in patients who underwent surgical treatment of kidney tumors: partial nephrectomy (PN) and radical nephrectomy (RN) and to identify risk factors for the development of acute kidney injury (AKI).Materials and methods. The study included 399 patients, of which 276 patients (69.17 %) underwent PN, 123 (30.83 %) underwent RN. According to the clinical stage of the disease, patients in the PN and RN groups were distributed as follows: cT1a – 160 (91.95 %) and 14 (8.05 %), cT1b – 99 (61.11 %) and 63 (38.89 %) and cT2a – 17 (26.98 %) and 46 (73.02 %), respectively. Operations were performed with open (1.0 %), laparoscopic (39.35 %) and robot-assisted (59.65 %) accesses. AKI was evaluated by the changes in serum creatinine and glomerular filtration rate before surgery and 1–3 days after in accordance with KDIGO criteria.Results. The overall incidence of AKI after surgical treatment for kidney cancer at stages cT1a–cT2a was 27.57 %. The incidence of AKI after RN was 65.04 %, after PN – 11.23 %. At stages cT1a, cT1b, cT2a, after nephron-sparing surgery and radical treatment, this indicator was 9.37; 11.11; 29.41 % and 71.43; 63.49; 65.22 %, respectively. For warm ischemia time below 15 and 20 minutes, AKI incidence did not exceed 8.3 and 13.2 %, respectively. For warm ischemia time >30 min, a dramatic increase in AKI incidence was observed.Conclusion. To preserve kidney function, PN is the operation of choice in surgical treatment of kidney tumors at stages cT1–cT2a. After RN, AKI development was observed 6 times more often than after PN. The following statistically significant predictors of AKI after PN were identified: presence of initial chronic kidney disease in patients, tumor size, operative time above 190 minutes, type of kidney ischemia used, and warm ischemia time above 25 minutes.