OBJECTIVES: Nighttime urinary frequency (nocturia), common in patients with overactive bladder (OAB), negatively impacts sleep quality. Three sleep-related patient-reported questionnaires were assessed with regard to ability to discriminate between patients with and without OAB. METHODS: Adult men and women with OAB symptoms for at least 3 months (≥8 micturitions per day; ≥2 micturitions per night; and ≥6 urgency episodes over 3 days per bladder diary) and without OAB symptoms (control group) completed several sleep questionnaires: Stanford Sleepiness Scale (morning and evening for 5 days), Epworth Sleepiness Scale, and Nocturia Quality of Life Questionnaire (N-QoL); t tests were performed between groups. RESULTS: A total of 43 participants with OAB and 10 healthy controls were enrolled. Mean age and proportion of men were similar in the OAB and control groups (63.7 vs. 55.6 years old [P=0.31], and 46.2% vs 40.0% male [P=0.53], respectively). Race, employment status, and education level were also similar between groups (all P>0.25). Mean scores on the Stanford Sleepiness Scale across the 5 days were significantly higher in the OAB group than the control group at time of awakening (3.0 vs. 2.0; P=0.0030) and at 7:00 pm (3.5 vs. 1.9; P=0.0006), indicating greater sleepiness.  Epworth Sleepiness Scale mean scores were also significantly higher in the OAB group than the control group (10.5 vs 4.1, respectively; P<0.0001), indicating greater daytime sleepiness. On the N-QoL, participants with OAB had significantly lower mean Total scores than controls (54.7 vs. 99.2; P<0.0001), Sleep/energy scores (55.9 vs. 100.0; P<0.0001), and Bother/concern scores (54.0 vs. 98.3; P<0.0001), indicating greater health-related quality of life impairment because of nighttime urination. CONCLUSIONS: The Stanford Sleepiness Scale, Epworth Sleepiness Scale, and N-QoL all effectively discriminate between participants with OAB symptoms and those without OAB symptoms.