Researchers have been exploring the possibility of a correlation between male circumcision and lowered risk of HIV infection almost since the beginning of the HIV/AIDS epidemic. Results from a randomised controlled trial in South Africa in 2005 indicate that male circumcision protects men against the acquisition of HIV through heterosexual intercourse, confirming the findings from 20 years of observational studies. Circumcised men in the South African trial were 60% (95% CI 32% to 76%) less likely to acquire HIV than their uncircumcised counterparts. A mathematical modelling study, based on the South African trial, estimates that the practice of male circumcision could avert two million new HIV infections and 300 000 HIV‐related deaths over the next 10 years in sub‐Saharan Africa. More recently, two randomised controlled trials in Kisumu, Kenya and Rakai, Uganda showed, respectively, 53% and 48% reductions in HIV acquisition among circumcised men than uncircumcised men in the trial. These results strongly suggest that male circumcision could play an important role in the struggle against the continued rise in new HIV infections. However, as observers noted at the 2006 XVI International AIDS Conference in Toronto, Canada, excitement about the potential epidemiological impact has overshadowed the debate over the difficult translation of research on male circumcision, into policy and practice. Similar calls for caution have been raised before and elsewhere.