PURPOSE: The study sought to assess demographics, clinical features, comorbidities, and polysomnographic features of a large cohort of clinic-based patients with rapid eye movement-predominant obstructive sleep apnea (REM-predominant-OSA) in both genders, while assessing the relationship between REM-predominant OSA in one hand and menopausal status and age on the other. METHODS: This prospective observational study was conducted between January 2003 and December 2017. REM-predominant OSA diagnostic criteria included an AHI of ≥5/h, with REM-AHI/non-REM-AHI of >2, a non-REM-AHI of <15/h, and a minimum of 15 min of REM sleep. Patients who had an AHI>5 events/h and did not meet the criteria for REM-predominant OSA were included in the non-stage-specific OSA group (NSS). RESULTS: The study consisted of 1346 men and 823 women (total=2169). REM-predominant OSA was diagnosed in 17% (n=369). The prevalence of REM-predominant OSA in women was 25% compared with 12% in men. Several independent associations of REM-predominant OSA were identified in the whole group, including age (OR: 0.97 [0.95-0.98], p<0.01), female sex (OR: 6.95 [4.86-9.93], p>0.01), REM sleep duration (min) (OR: 1.02 [1.02-1.03], < 0.01), and time with SpO2 <90% (mins) (OR: 0.97 [0.95-0.99], < 0.01), hypertension (OR:0.67 [0.45-0.99], 0.04) and asthma (OR: 2.19 [1.56-3.07], < 0.01). The prevalence of REM-predominant OSA in premenopausal and postmenopausal women was 35% and 18.6% (p< 0.01), respectively. Among women, age was an independent correlate (OR: 0.97 [0.94-0.99], p=0.03; however, menopausal status was not. CONCLUSION: REM-predominant OSA is prevalent among clinic-based patients with OSA. A younger age and female sex were independent correlates of REM-predominant OSA. Among women, a younger age but not menopausal status was a correlate of REM-predominant OSA. Asthma was independently associated with REM-predominant OSA.