PURPOSE:To understand the characteristics of a minority of Australian gay and bisexual men (GBM) who, despite an increase in the number and availability of HIV risk reduction strategies, do not consistently use a strategy to protect themselves from HIV. METHODS:This analysis is based on data from 2,920 participants in a national, online, prospective observational cohort study. GBM who never or rarely used HIV risk reduction strategies (NRR) were compared with two groups using multivariate logistic regression: i) GBM using pre-exposure prophylaxis (PrEP) and ii) GBM frequently using risk reduction strategies (FRR) other than PrEP. RESULTS:Compared to PrEP users, NRR men were younger (p<0.0001), less socially engaged with gay men (p<0.0001) and less likely to have completed a postgraduate (p<0.05) or undergraduate degree (p<0.05). They were also less likely to have recently used amyl nitrite (p<0.05), erectile dysfunction medication (p<0.05) and cocaine (p<0.05) in the previous 6 months. Compared with FRR men, NRR men were less likely to have completed a postgraduate (p<0.0001) or undergraduate degree (p<0.05), scored higher on the sexual sensation-seeking scale (p<0.0001) and were more likely to identify as versatile (p<0.05), a bottom (p<0.05) or very much a bottom (p<0.05) during anal sex. CONCLUSIONS:NRR men were largely similar to other Australian GBM. However, our analysis suggests it may be appropriate to focus HIV prevention interventions on younger, less socially engaged and less educated GBM, as well as men who prefer receptive anal intercourse to promote the use of effective HIV risk reduction strategies.