The aim of study: to evaluate the relations nature between urodynamic indexes and indexes showing kidneys function in patients with benign prostate hyperplasia (BPH).Patients and methods: complex urological investigation of 291 patients with BPH (middle age 61,3 ± 0,7 years) including urodynamic investigation was done, and for 63 patients the evaluation of glomerular filtration rate was carried out as well.Results: A power of detrusor’s contractility makes an influence to the serum kreatinine level after surgical treatment of BPH (r = –0,54; p = 0,048). The relation between the power of detrusor’s contractility (r = –0,2; p = 0,047) and urea level was showed up, so in case of decreased bladder contractility the level of urea becomes increased. Presence and grade of infravesical obstruction did not influence on kreatinine and urea concentration in a blood (r = –0,16; p = 0,22; r = –0,02; p = 0,89). If detrusor’s contractility become decreased the glomerular filtration rate is decreased too (r = 0,41; p = 0,035) and enlargement of calyxes-pelvic system is present (CPS) (r = 0,41; p = 0,035). The detrusor’s pressure (r = 0,52; p = 0,01) and the bladder capacity (r = 0,44; p = 0,035) in the process of maximal spontaneous contractility make in influence into the CPS as well. At the same time no relations (r = 0,06; p = 0,74) between detrusor’s hyperactivity and enlargement of CPS were found.Сonclusion. Decreasing of detrusor’s contractility and the presence of uncontrollable constructions in case of large volumes of bladder inflating make a bigger influence to the functional condition of upper urinary tract at the patients with benign prostate hyperplasia then a presence and grade of infravesical obstruction.