While the expansion of antiretroviral therapy (ART) in sub-Saharan Africa has reduced morbidity and mortality from HIV/AIDS, it has increased concern about drug resistance. The Microbicide Trials Network 009 study assessed the prevalence of drug-resistance mutations among women at clinical sites in Durban, South Africa who tested seropositive for HIV-1 at screening for the VOICE trial. The objective of this paper was to identify characteristics and behaviors associated with drug resistance. Factors found to be significantly associated with increased resistance were high perceived risk of getting HIV and prior participation in a microbicide trial, a likely proxy for familiarity with the health care system. Two factors were found to be significantly associated with reduced resistance: having a primary sex partner and testing negative for HIV in the past year. Other variables hypothesized to be important in identifying women with resistant virus, including partner or friend on ART who shared with the participant and being given antiretrovirals during pregnancy or labor, or the proxy variable—number of times given birth in a health facility—were not significantly associated. The small number of participants with resistant virus and the probable underreporting of sensitive behaviors likely affected our ability to construct a comprehensive profile of the type of HIV-positive women at greatest risk of developing resistance mutations.