Objective To investigate the barriers to HIV testing among Australian gay men. Methods: An online survey was conducted to explore reasons for avoiding and delaying testing for HIV; 519 non-HIV-positive men completed the online survey. Results: Most non-HIV-positive men (92.9%) had been tested for HIV, with 75.4% indicating they had been tested in the previous year. The most common reasons for avoiding or delaying testing were a belief that they had not done anything risky (41.2%) and the need to return for a second clinic visit to receive results (40.3%). Among men who engaged in unprotected anal intercourse with casual partners (UAIC), those who had not been recently tested were more likely to cite the lack of any symptoms as reasons for not having tested (adjusted odds ratio: 2.34; 95% confidence interval: 1.03–5.31; P = 0.041). Conclusions: For men who do not engage in risky sex, the decision not to test is probably reasonable, but those who engage in noncondom-based risk reduction may be at some increased risk and should be encouraged to test relatively often. Changes to Australia’s national HIV testing policy may ameliorate some of the need to return for second clinic visits to receive results, but the policy still requires full implementation, including the introduction of rapid point-of-care HIV testing to Australia. Among men who engage in UAIC, there appears to be a particular need for information about the benefits of early treatment after HIV diagnosis and about the relative likelihood of experiencing HIV seroconversion illness.