Introduction. Purulent pyelonephritis is a complicated urinary tract infection with one of the most severe currents. It represents a serious clinical problem associated with the complexity of the choice of diagnosis and the optimal active treatment strategy, as well as the need for subsequent rehabilitation of this category of patients.Purpose of the study. Studying of the immediate and remote results of the kidneys` functional state in patients who have undergone purulent pyelonephritis using a differentiated approach to treatment tactics.Materials and methods. The study included 84 patients who underwent purulent pyelonephritis at the age of 15 to 70 years old and were treated at the Botkin City Clinical Hospital from 1999 to 2007. The patients were divided into three groups depending on the method of treatment: group 1 - open surgery of 18 patients (21.4%); group 2 - percutaneous drainage methods - 38 (45.3%); group 3 - conservative therapy - 28 (33.3%) patients. Examination of patients included dynamic nephroscintigraphy and complex ultrasound. It was performed in time after treatment after 12, 36 and 60, 84 months.Results. During the 7-year observation of patients, it was found that a more pronounced renal dysfunction and perfusion occurred during all periods of observation after undergoing open surgery according to Doppler sonography. Restoration of renal function occurred in shorter observation periods after the use of percutaneous kidney drainage and conservative treatment.Conclusion. Based on the data obtained, it can be concluded that a differentiated approach to the choice of tactics for the treatment of patients with purulent pyelonephritis is reasonable. Accordingly, it should be introduced into clinical practice of urological departments that provide emergency care to urological patients.