Objective We assessed interest in using rectal microbicides to prevent HIV transmission among gay men in Australia.

Methods A national online survey was conducted in 2013. Interest in using rectal microbicides was measured on a seven-item scale (α=0.81). Factors independently associated with greater interest in using a microbicide were identified using multivariate logistic regression.

Results Data were collected from 1223 HIV-negative and untested men. Mean age was 31.3 years (SD=10.8, range 18–65); 77% were born in Australia and 25% reported any condomless anal sex with a casual partner in the previous 6 months. Overall, there was moderate interest in using rectal microbicides (M=3.33, range 1–5). In multivariate analysis, greater interest in using microbicides was independently associated with being born outside Australia (adjusted OR (AOR)=1.59; p=0.009), greater self-perceived likelihood of becoming HIV positive (AOR=3.40; p<0.001), less uncertainty about the efficacy of microbicides (AOR=0.65; p=0.009), any condomless anal sex with casual partners in the previous 6 months (AOR=1.78; p=0.03) and ever having received postexposure prophylaxis (AOR=1.53; p=0.04). Interest in using microbicides was not associated with age, number of male sex partners or the HIV status of regular male partners.

Conclusions Interest in using rectal microbicides was associated with self-perceived vulnerability to HIV, engaging in sexual practices that increase the risk of HIV acquisition and less uncertainty about the efficacy of microbicides. There appears to be a group of men who would benefit from, and are highly motivated to use, a rectal microbicide product.