PURPOSE: We estimated the prevalence of nocturia in the United States male population and identified associated factors. MATERIALS AND METHODS: Data were analyzed for 5,297 men (20 years old or older) who participated in the 2005-2006 and 2007-2008 cycles of the NHANES, a cross-sectional survey of the United States noninstitutionalized population. Getting up 2 or more times at night to urinate was coded as nocturia. Potential factors included age, race/ethnicity, education, waist circumference, self-reported health status, chronic diseases, and prior diagnosis of benign prostatic enlargement and/or prostate cancer (men 40 years old or older). Prevalence and prevalence odds ratios were estimated from a multivariable logistic regression analysis using appropriate sampling weights. RESULTS: The prevalence of nocturia was 21% (weighted 95% CI 19.3-23.0). Nocturia increased in prevalence with age (p<0.001) from 8.2% (CI 6.7-10.2) in men 20 to 34 years old up to 55.8% (CI 51.3-60.2) in men 75 years old or older. More nonHispanic black men had nocturia (30.2%, CI 26.7-34.1) than other racial/ethnic groups (20.1%, CI 18.1-22.1, p<0.001). Significant factors included 10-year increase in age (POR 1.5, CI 1.5-1.6), nonHispanic black race/ethnicity (POR 2.0, CI 1.6-2.7), fair/poor self-rated health (POR 1.5, CI 1.2-1.9), major depression (POR 2.5, CI 1.6-3.9), hypertension (POR 1.4, CI 1.0-1.9) and arthritis (POR 1.3, CI 1.0-1.7). Among men 40 years old or older benign prostatic enlargement (POR 1.4, CI 1.1-1.8) and prostate cancer (POR 1.6, CI 1.0-2.4) were associated with nocturia. CONCLUSIONS: After adjusting for age and race norms nocturia was common among United States men. NonHispanic black men had greater odds of nocturia even when controlling for other factors.