The article represents the authors’ own observation of the patient with xanthogranulomatous pyelonephritis (XPN). Xanthogranulomatous pyelonephritisis a rare form ofchronic bacterial calculous pyelonephritis. Factors predisposingto thedevelopmentof xanthogranulomatous pyelonephritis include the following: the impairment of theurinary flowalong theurinarytract, type II diabetes mellitus, and chronic inflammation of the kidney. XPN is an uncommon cause of chronic pyelonephritis resulting in non-functioning kidneys and poses a preoperative diagnostic dilemma which may mimic other malignant diseases of a kidney (renal cell carcinoma, leiomyosarcoma) and acute pyelonephritis as a bacterial infection causing inflammation of the kidneys (a renal carbuncle). The patient was examined at the urology clinic of .Grodno State Medical University: general clinical blood and urine tests, ultrasound examination, X-ray computed tomography - native and with contrast enhancement, magnetic resonance imaging were performed. The patient underwent nephrectomy due to the impossibility of organ-preserving surgery - removal of a volumetric formation located at the hilum of the kidney and adjacent to the vessels. Histopathologyof the specimen wasconcludedas xanthogranulomatouspyelonephritis. The patientsunderwentMR examinations, ultrasound examination and X-ray computed tomography with contrast enhancement, but adiagnosisofxanthogranulomatous pyelonephritiswas not confirmed unequivocally. The final diagnosis is usually established only after histologic examinationof biopsy specimens of removed kidney.