Female sex workers are at high risk of both HIV infection and unintended pregnancy. Although programs and policies targeting female sex workers emphasize HIV prevention and condom promotion, they typically pay limited attention to the family planning needs of these women.Correct and consistent condom use is highly effective at preventing HIV and other STIs, but condoms are not the most effective contraceptive method.1 In contrast, nonbarrier modern contraceptive methods (such as oral contraceptives, injectables and sterilization) are highly effective at preventing pregnancy, but confer no protection against STIs. For protection against both unwanted pregnancy and STIs, one option is a dual method approach: consistent use of condoms in conjunction with a more effective nonbarrier method. However, for many women-particularly female sex workers, who have frequent sex with multiple partners-the use of two methods for every sex act may be burdensome and unrealistic. For these women, a more feasible dual protection strategy might be a singlemethod approach: consistent condom use alone. Most dual protection research has taken place in developed countries, where contraceptive prevalence is relatively high. The reported prevalence of dual method use among American women ranges from 7% to 38%. 2-7 A handful of studies on dual protection have been conducted in Sub-Saharan Africa, where both HIV and unwanted pregnancy are critical public health challenges. In South Africa and Botswana studies, dual method use at last sex ranged from 4% to 28%. [8][9][10][11] However, a limitation of most research on dual protection is the focus on method use at last sex, rather than consistency of simultaneous condom and other contraceptive use at each coital act. These "last sex" measures of dual method use may not reflect optimal dual protection against both pregnancy and disease.Little is known about the dual protection strategies employed by female sex workers, and measurement of their contraceptive behaviors is complicated by the fact that their condom use varies across partners. Specifically, female sex workers use condoms less consistently with more intimate, noncommercial partners than with paying clients. [12][13][14] In addition, their reported condom use at last sex or with their most recent partner likely will not accu-