The objective of this study was to evaluate the female sexual function in relation to hormonal status in pre-and postmenopausal women with obstructive sleep apnea (OSA). A total of 43 premenopausal (mean age 42.1±4.9) and 58 postmenopausal (mean age 59.9±4.8) women were included in the study. All women filled out the Epworth sleepiness scale (ESS), the Beck Depression Inventory (BDI) and the Female Sexual Function Index (FSFI). Testosterone, estradiol and progesterone were measured. After polysomnography, women were allocated to a not-severe OSA group (Apnea--Hypopnea Index (AHI) 10--30) and a severe OSA group (AHI 430). Healthy subjects comprised the control group. Severe OSA women in both pre-and post-menopausal group were found to have significantly lower mean FSFI score (16.5 ± 4.0 and 16.9 ± 4.7, respectively) compared with not-severe OSA (23.4 ± 5.5, Po0.01 and 21.8 ± 7.5, Po0.05) and control subjects (27.0 ± 5.5, Po0.01 and 24.0±6.7, Po0.01). Progesterone, which was significantly lower in severe OSA premenopausal women (0.26±0.2) compared with not-severe OSA (0.55 ± 0.14, Po0.01) and control group (0.62 ± 0.16, Po0.01), correlated significantly with FSFI (r ¼ 0.39, Po0.01). Our study demonstrated that OSA is associated with sexual dysfunction in both premenopausal and postmenopausal women in a dose-related fashion. Regarding premenopausal women, our results indicated that progesterone may play a role in the association between OSA and female sexual dysfunction.