This paper presents a logical analysis of the paths by which gender inequality is likely to affect the heterosexual transmission of HIV. Non-use of condoms, the combination of a sexual double standard and frequent use of female prostitutes, and a high prevalence of curable sexually transmitted diseases are considered. The 'circulation' of women as sexual and reproductive gifts, which is a near-universal feature of human societies, explains men's use of prostitutes and promiscuity, and contributes to high STD prevalence. It may also contribute to the non-use of condoms, although a separate analysis suggests this is not always the case. The empowerment of women thus might help to slow the spread of HIV/AIDS. Even more effective in countries with large commercial sex sectors would be the empowerment of female sex workers.