In this study we sought to identify the social and behavioural characteristics of Australian gay and bisexual men who had and had not tested for HIV during their current relationship. The results were based on 2012 and 2013 data collected from ongoing cross-sectional and community-based surveys held in six Australian states and territories. One thousand five hundred and sixty-one non-HIV-positive men reported that they were in a primary relationship. The majority of gay and bisexual men in primary relationships had tested for HIV during the relationship (73.4 %). Among men who had not tested during the relationship, almost half of these men had never tested for HIV. As untested men within relationships are potentially at risk of acquiring and transmitting HIV to their partners unknowingly, it is important to promote HIV testing to these men.