Abstract Introduction Nocturia (waking from sleep to urinate) is the most common cause of sleep interruption among older adults and nocturnal polyuria (NP; increased sleep time urine production) is its most common cause. Conversely, poor sleep with repeated awakenings contributes to both nocturia and NP. However, whether a behavioral intervention to reduce repeated awakenings can improve nocturia and NP has not been examined in a clinical trial. The current study assesses the effect of Brief Behavioral Treatment for Insomnia (BBTI) on nocturia and NP in older adults. Methods Fifty-six community-dwelling older adults (mean age, 72±6 years; 64% women) with nocturia frequency ≥2 per night were randomized to receive BBTI vs information-only control (IC). All participants completed a 3-day voiding and sleep diary to assess nocturia, and sleep. Participants with a nocturnal polyuria index (NPi; percent of 24-hour urine volume excreted at night) ≥35% were considered to have NP. Results At baseline, nocturia frequency correlated with total sleep time (r=.54, p< 0.001) and duration of the first uninterrupted sleep period (FUSP, r=-.40, p=0.004) after adjusting for age and body mass index. BBTI significantly improved nocturia frequency compared to the IC group (-1.0±0.7 vs -0.3±0.9; p=.02). FUSP increased by 54±77 minutes in the BBTI group and NPi decreased by 7.1±13.2%, but these changes were not significantly different from the IC group. Change in NPi correlated with change in FUSP (r=-.36, p=.01; longer FUSP associated with lower NPi), but not with change in total sleep time (r=-.04, p=.7). Conclusion In older adults with nocturia, behavioral treatment directed solely at sleep also improves nocturia. Improving sleep continuity in the first half of the night and increasing FUSP, but not total sleep time, may also improve NP. Support (if any) NIA AG060292