Gay and bisexual men (GBM) use oral erectile dysfunction medications (EDMs) often with little evidence of medical indication necessitating their use.To investigate the prevalence, contexts, and motivations for oral EDM use and its relation to sexual risk behavior.A total of 2,250 Australian GBM completed an online survey of licit and illicit drug use and their associated behaviors. Multivariate logistic regression analysis identified factors associated with use of EDMs in the previous 6 months and, for those who had used EDMs, factors associated with use on a weekly basis.Any EDM use and at least weekly use in the previous 6 months.The median age of the sample was 33.0 years (range = 16-81). Two thirds (67.7%) reported no lifetime history of EDM use. Approximately 1 in 10 participants (11.1%) had last used an EDM more than 6 months previously. In the previous 6 months, 11.5% reported using EDMs less than monthly, 5.3% reported using EDMs approximately monthly, and 4.5% reported using EDMs at least weekly. Of men who had used EDMs in the previous 6 months, common reasons cited for its use were to maintain an erection for longer (73.3%), to make it easier to "get hard" (67.3%), and difficulty in attaining or maintain an erection (53.5%). Use of EDMs in the previous 6 months was associated with illicit drug use and higher rates of sexual risk behavior. Weekly users were more likely to have severe anxiety than less frequent users.The use of EDMs in the context of intensive sex partying, with the associated potential for increased risk of HIV transmission and illicit drug use, indicates a need to consider the use of EDMs among GBM in HIV prevention and minimizing harm.This large-scale study of drug use among GBMs includes comprehensive detailed data on their history of use and rationales for use. Our online methodology potentially decreases social desirability bias in reporting illegal or stigmatized behaviors. This volunteer online convenience sample might not be representative of all GBMs in Australia.GBMs who used an oral EDM in the previous 6 months often used it for recreational purposes, but many of those who used it on a weekly basis also might have used it for therapeutic reasons. GBMs often use EDMs to enhance their sexual experiences often in the context of intensive sex partying (which can include risky sexual behavior). Hammoud MA, Jin F, Lea T, et al. Off-Label Use of Phosphodiesterase Type 5 Inhibitor Erectile Dysfunction Medication to Enhance Sex Among Gay and Bisexual Men in Australia: Results From the FLUX Study. J Sex Med 2017;14:774-784.