Introduction. Nocturia being a part of LUTS and BPH symptomatology has been historically associated with prostate or bladder pathology. Currently, the diagnostic tools used to assess the severity of LUTS/BPH symptoms do not allow the differential diagnosis between nocturia of obstructive or irritating etiology and nocturnal polyuria. The International Society of Continence (ISC) classifies nocturnal polyuria as the volume of nocturnal urine divided by the 24-hour urine volume, this ratio being defined as the nocturnal polyuria index (NPi). Thus, according to ISC, nocturnal polyuria is when NPi> 20% in young people and NPi> 33% in people over 65 years old. Material and methods. A group of 44 patients (18 patients <65 years and 26 patients> 65 years) with nocturnal symptoms as the main complaint was analyzed. Main inclusion criteria - NPi> 33%. 33 patients - with an anamnesis of evaluation and treatment, 11 patients addressed primarily. The patients age ranged from 41 to 72 years, with an average of 54.2 years. The results of the following assessments were analyzed: IPSS standardized questionnaire, TRUS-P with residual urine and Stamey-Meares probe. Results. According to the results of IPSS, 34(77,27%) were assessed with mild severity and 6(27,73%) with moderate symptomatology. The analysis of the answers identified 0 points for questions 1-6 in 35(79,54%) of the cases, most of the points being accumulated on the account of questions 7 and 8 for all those included. At question 7, 40(90,9%) patients get 3 to 5 points and 27(79,41%) of those with mild symptoms get 5 or 6 points for question 8. The volume of the prostate was estimated from 23,4ml to 88,56ml, with an average of 45,34ml. Absent residual urine was identified in 37(84,1) and in 7(15,9%) it was below 50 ml. The positive Stamey-Meares test was identified at 7(15,9%). Of those with a history of evaluation and treatment, 26(78,8%) were treated for prostatitis and 13(39,4%) had prostate surgical treatment. Conclusions. The diagnostic tools for LUTS / BPH are insufficient to assess all the etiological causes of nocturia. Nocturia significantly affects patients’ quality of life, and the total IPSS score wrongly assess the degree of impairment.