Finasteride is 5α-reductase inhibitor that is FDA approved for the treatment of benign prostatic hypertrophy and androgenetic alopecia in men. Free testosterone is converted by 5α-reductase to the more potent androgen 5α-dihydrotestosterone. Finasteride, which crosses the blood-brain barrier, therefore lowers overall androgen activity. A decrease in androgen levels has been associated with OSA and lower sleep efficiency in some studies. Recently the ‘post-finasteride syndrome’ (PFS) consisting of sexual difficulties, several neurologic/psychologic symptoms and insomnia has been recognized. To our knowledge there are no reports of OSA with finasteride. The FAERS database (January 1, 2004-June 30, 2017, total count of individual safety reports or ISR =9,553,117) was used to examine ISR of OSA and insomnia where finasteride was documented as the primary suspect. Medical Dictionary for Regulatory Activities (MedDRA) preferred terms (PTs) were used to select ISRs designating OSA (PT [MedDRA code] Sleep apnoea syndrome [10040979]) and Insomnia (PT [MedDRA code] included Insomnia [10022437], Initial insomnia [10022035], Middle insomnia [10027590], and Terminal Insomnia [10068932]) as the adverse event (AE). Reporting odds ratios (ROR) with 95% confidence intervals (CI) were calculated to assess baseline risk of OSA and insomnia when finasteride was used for any indication versus the risk of OSA and insomnia with all other medications in FAERS used for any indication. All ISRs where data on sex was available (89/145) involved males; age was coded in only 3/145 ISRs. The odds of OSA with finasteride for any indication versus OSA with all other medication in FAERS used for any indication revealed ROR=5.73(95% CI 4.86–6.75, z=20.866, p