BackgroundNocturia is one of the most prevalent and bothersome lower urinary tract symptoms (LUTS) in men, leading to increased morbidity and mortality and a considerable economic burden on healthcare systems. Understanding its natural history, effect of pharmacotherapy, and predictors of failure of pharmacotherapy would allow optimised patient management. ObjectiveTo evaluate the prevalence and effect of clinically relevant nocturia (crN) on quality of life in a contemporary cohort of European men aged ≥50 yr in a “real-life” setting, to understand its natural history, to detect any effect of pharmacotherapy, and to identify predictors of pharmacotherapy failure. Design, setting, and participantsThis is a secondary analysis of the data from the Evolution Registry—a European, multicentre, prospective, observational registry, conducted in five European countries within a sample of general practitioners’ and urologists’ clinics. A consecutive sample of 2175 men aged ≥50 yr with LUTS in association with benign prostatic enlargement was enrolled between February 2010 and April 2011, and followed up for 2yr. Overall, data from 1838 men were suitable for analysis. Outcome measurements and statistical analysisThe primary outcome was evaluation of the baseline incidence of nocturia in the study population. Secondary outcomes included the impact of nocturia on quality of life, efficacy of pharmacotherapy, and predictive factors associated with persistence of nocturia. Descriptive statistics were used to examine the data. Logistic regressions were used to analyse associations between comorbid conditions and risk factors in men with nocturia. Results and limitationsOverall, 1198 men (65%) reported crN (two or more voids per night). This increased age dependently from 59% in the 50–59-yr age group (n=74) to 89% in the 80–99-yr age group (n=25). Overall, the incidence of crN improved in those who commenced pharmacological treatment at study entry, from 69% at baseline to 49% at 24 mo (p<0.00001). This was statistically significant only in those <80 yr old. A weak correlation was found between the severity of nocturia at baseline and quality-of-life scores on the International Prostate Symptom Score questionnaire (r=0.33, p<0.001). Of the patients treated with an alpha-blocker or a 5-alpha reductase inhibitor, 62% still had crN at 24 mo. ConclusionsAlmost two-thirds of men in the Evolution Registry reported clinically significant nocturia with increased incidence with age. Despite prostate-targeted treatment, most patients, especially older men, still had persistent or worsening nocturia at 2-yr follow-up, and in this study, it was not possible to identify specific clinical factors that predicted those who could respond well to treatment in this regard. Patient summaryThis large study of men from five different European countries has shown that waking up at night to pass urine (nocturia) is very common and becomes more common with older age, and treatments that target the prostate do not significantly improve symptoms over 2yr in most men.