Randomized controlled trials in sub-Saharan Africa have shown that adult male circumcision reduces the risk of HIV acquisition in men by about 60%. In this article, we review recent data on the association of male circumcision and HIV/sexually transmitted infection in men and women. This includes a summary of data showing some evidence of an effect of male circumcision against genital ulcer disease, HSV-2 infection, human papillomavirus and Trichomonas vaginalis, but not Chlamydia trachomatis or Neisseria gonorrhoea in men. Longitudinal studies among HIV discordant couples suggest that male circumcision may provide some direct long-term benefit to women, which may start after complete wound healing. Circumcision may also protect against HIV acquisition in men who have sex with men (MSM) and those who practice unprotected anal intercourse (either exclusively or predominantly), although these data are not consistent. To date, there is little evidence from the few studies available of either unsafe practices or reported increases in risky behaviour, or adverse changes in sexual satisfaction and function. As countries in southern and eastern Africa scale up services, operational research will likely be useful to iteratively improve programme delivery and impact while identifying the best methods of integrating safe male circumcision services into HIV prevention strategies and strengthening health systems.