Introduction: To examine the relationship of nocturia to objective sleep quality and subjective sleepiness and fatigue in women with OSA. Methods: Participants were 20 consecutive female patients, referred to the sleep laboratory for suspicion of sleep disordered breathing at INCMNSZ in México City. We excluded patients taking diuretics, neurodegenerative disease, or were on CPAP treatment. Informed consent was obtained, and the study was approved by the local ethics committee. Twenty women mean age 50.9 ± 14.5 years old, BMI 28.1 ± 6.8 (SD), underwent diagnostic polysomnography (PSG) in laboratory. Validated questionnaires for depression, fatigue, sleepiness were administered prior to the PSG night. Nocturia was defined as ≥2 voids per main habitual sleep period. Results: By history, nocturia was present in 50% of the women. Mean AHI 8.99 ± 19.3, mean ODI 4% 23.67 ± 34.33. Respiratory parameters did not correlate with the presence of nocturia. Age was positively correlated with nocturia rho=0.613, p=0.004. N2 sleep %, REM sleep %, and sleep efficiency were all lower in relation to nocturia (rho=-0.540, p=0.014; rho=-0.582, p=0.007; rho=-0.533, p=0.016, respectively). Surprisingly, Periodic Leg Movement Index was positively associated with nocturia rho=0.491, p=0.028, whereas the Epworth Sleepiness, fatigue, and depression scale scores were unrelated. Conclusion: Nocturia is associated with lower sleep efficiency, N2%, and REM sleep %, but not with measures of OSA. The relationship to PLMS may have precedent in previous population-based study that reported an association between RLS and nocturia. Support (If Any): Support (No)