OBJECTIVES:HIV-positive women have particular needs for contraception to avoid unwanted pregnancy, to protect their own health and to eliminate the risk of transmitting HIV to an infant. In 2004, the United Nations described a four-element strategy to preventing mother-to-child transmission of HIV; the second element is preventing unintended pregnancies among HIV-positive women. However, fertility preferences among HIV-positive women who know their status remain poorly understood. This study seeks to demonstrate the degree to which knowledge of one's own serostatus is associated with fertility preferences and contraceptive demand and use. METHODS:This study uses Demographic and Health Surveys data and bivariate and multivariate methods to assess the contribution of a proxy variable for knowledge of own HIV serostatus to women's fertility desires, demand for contraception and contraceptive method choice for Zambia, Swaziland, Zimbabwe and Lesotho. RESULTS:Knowledge of one's own HIV-positive serostatus is significantly associated with a desire to limit childbearing with contraceptive use, but not necessarily with unmet need for contraception. HIV-positive women who know their status are more likely than other women to use condoms. CONCLUSION:HIV-positive women who know their serostatus exhibit fertility desires and contraceptive behaviors that are different from those of other women. These findings support the argument that efforts to scale up the second element of the strategy to prevent mother-to-child transmission of HIV should be accelerated: it is a cost-effective, rights-based approach to preventing incidence of mother-to-child transmission of HIV. Scaling up requires full commitment by both reproductive health/family planning and HIV constituencies to concerted integration at all levels of program planning, coordination and implementation.