BACKGROUND AND AIMS:Gay, bisexual and other men who have sex with men (GBM) use alkyl nitrites ('poppers') at higher rates than other populations to functionally enhance sexual experiences. Their use has been associated with HIV sexual risk behaviours including receptive anal sex. We investigate the prevalence, frequency, and motivations for poppers use and their relationship with HIV risk. We also discuss the implications of the recent scheduling changes to poppers by the Australian Therapeutic Goods Administration. METHODS:Data were drawn from the Following Lives Undergoing Change (Flux) study, a prospective observational study of licit and illicit drug use among GBM. Between 2014 and 2018, 3273 GBM enrolled in the study. In 2018, 1745 GBM provided data relating to frequency of and motivations for poppers use and were included in this analysis. RESULTS:Median age was 33 years (IQR 25-46) and 801 GBM (45.9%) had used poppers in the previous six months ('recent use'). Among these men, 195 (24.3%) had used them weekly or more frequently. Most recent users (77.4%) reported using poppers for a 'buzz' during sex or to facilitate receptive anal intercourse (60.8%). The majority (57.7%) of HIV-negative men reporting recent poppers use were concurrently taking HIV pre-exposure prophylaxis. Recent poppers use was independently associated with receptive anal intercourse with casual partners (aOR 1.71; 95%CI 1.35-2.16) and chemsex (aOR 4.32; 95%CI 3.15-5.94). Poppers use was not associated with anxiety, depression, or drug-related harms. Only 15.4% of current users indicated they would stop using poppers if they were criminalised; 65.0% said they would 'find other ways' to obtain them. CONCLUSIONS:Poppers are commonly used by Australian GBM to functionally enhance sexual experiences, particularly to facilitate receptive anal intercourse. Few men experienced drug-related harms from poppers use. Regulatory changes must ensure potential harms from popper use are minimised without increasing barriers to access or perpetuating stigma.