Although discrimination and stigma are recognised determinants of HIV-risk sexual behaviours in the LGBTI population, related data are scarce. In particular, the 'pathways' between these determinants and HIV-risk sexual behaviours are understudied. The main objective of the present study was to fill this knowledge gap by analysing - in a worldwide sample - the relationships between multiple dimensions of homophobia, general propensity to take risks, and HIV-risk sexual behaviours. We used data from UNAIDSs Global LGBTI Happiness survey, which was conducted among 115 000 individuals in 204 countries in 2019/2020. Structural/institutional homophobia is defined at the country level and was measured mainly by assessing the number and type of restrictive institutional laws and homophobic attitudes. Structural equation modelling was performed to identify associations between different dimensions of homophobia and HIV-risk sexual behaviours in participants who self-identified as cisgender, transgender, nonbinary, intersex, gay, bisexual and queer. In our worldwide sample of 69 640 participants, we found that structural homophobia predicted local homophobia (β = 0.040, (95 %CI = 0.027-0.053)), homophobia at work (β = 0.022, (95 %CI = 0.010-0.034)), family homophobia (β = 0.19, (95 %CI = 0.18-0.20)), and HIV-risk sexual behaviours (β = 0.069, (95 %CI = 0.059-0.078)). Results indicate that local homophobia and homophobia at work were directly and positively associated with HIV-risk sexual behaviour (β = 0.088, (95 %CI = 0.072-0.10) and 0.013, (95 %CI = 0.001-0.026), respectively). Institutional (/structural) homophobia was also indirectly associated with general risk-taking and HIV-risk sexual behaviour, mediated by individual homophobia. Our findings suggest that structural homophobia was associated with HIV-risk sexual behaviours through both direct and indirect pathways. In the context of limiting HIV-risk sexual behaviours, within the bigger picture of curbing the HIV epidemic, it is essential to prioritize implementing policies which eradicate homophobic violence, and which defend the rights of sexual and gender diverse people.

