Background Rapid HIV testing was introduced at 12 clinics in New South Wales (NSW) for routine testing and promoted with social marketing. The effect of the availability of rapid HIV testing on testing frequency among gay and bisexual men (GBM) was evaluated. METHODS:An observational design using patient data from 12 clinics was used. The primary outcome was the mean number of HIV tests in 12 months. The intervention group comprised GBM who had one or more rapid tests from October 2013 to September 2014 and this was compared with two control groups; a concurrent group (no rapid test in the same period) and a historical group (attended between July 2011 and June 2012). Independent sample t-tests were conducted to compare mean number of tests among men in the intervention, concurrent and historical groups. Multivariate logistic regression was used to assess the association between rapid HIV testing and testing frequency. RESULTS:Men in the intervention group (n = 3934) had a mean of 1.8 HIV tests in 12 months, compared with 1.4 in the concurrent group (n = 5063; P < 0.001) and 1.4 in the historical group (n = 5904; P < 0.001); testing frequency was higher among men at increased risk of HIV in the intervention group compared with the other two groups (mean 2.2, 1.6 and 1.5 respectively; P < 0.001). Membership of the intervention group was associated with increased odds of having two or more HIV tests in 12 months (AOR = 2.5, 95%CI 2.2-2.8; P < 0.001) compared with the concurrent group, after controlling for demographic and behavioural factors. CONCLUSION:Introducing and promoting rapid HIV testing in clinics in NSW was associated with increased HIV testing frequency among GBM.