HIV spread rapidly in Zimbabwe in the mid-late 1980s. By the mid-1990s, one-quarter of adults in the country were infected with HIV. HIV-1 subtype C is believed to be the predominant sub-type within the country and its spread has been mediated overwhelmingly by heterosexual sex. Sexual networks shaped by cultural and colonial influences, and the combination of a relatively high level of development and marked socio-economic inequalities, have facilitated the spread of HIV infection into the majority rural population, and have thereby fueled the large national epidemic. Classic sexually transmitted infections such as syphilis, gonorrhoea and Chlamydia have been controlled during the epidemic through a pioneering syndromic management programme, but Herpes simplex virus type 2 is extremely common. Male circumcision is only practised in minority groups. Blood transfusions were screened for HIV from an early stage in the epidemic and there is little evidence that contaminated needles have made more than a modest contribution to HIV transmission. The sociodemographic effects of the epidemic have been devastating and include sustained, crisis-level adult mortality, particularly in the most economically-active age-groups, a reversal of previous gains in early childhood survival, a rapid decline in population growth, and an inexorable rise in orphanhood. Since the late 1990s there have been signs of a leveling out in the HIV epidemic and of a decline in HIV incidence. There is evidence of reductions in rates of sexual partner change and of a decline in HIV prevalence in young people. These encouraging trends may reflect saturation of the epidemic within high risk groups, heightened mortality due to ageing of HIV infections, and changes in behaviour adopted in the face of the extreme adult mortality. Zimbabwe’s well-educated population and extensive primary health care network are conducive to a relatively rapid response to the HIV epidemic and the Government’s intensified efforts to control HIV transmission supported by those of its partners are also likely to have played a part in placing a brake on the national epidemic.