Three decades after the first government-funded HIV prevention campaign in 1985, gay and bisexual men (GBM) remain the population most at risk of infection in New Zealand. We review the major determinants of the elevated HIV risk for GBM, describe New Zealand's prevention response over the first 30 years, and summarise the public health record. HIV incidence among GBM is driven by the heightened biological efficiency of HIV transmission during unprotected anal intercourse, dense sexual partnering networks, and endemic HIV prevalence. Responses in New Zealand have emphasised evidence-based primary prevention by condom use, which were implemented in communities and supported by comprehensive public health action. New Zealand has a good international HIV prevention record among GBM, however HIV diagnosis rates are now higher than they were during the epidemic nadir of the late 1990s. Lessons from the first three decades must underpin future HIV control efforts.