Plasma levels of human immunodeficiency virus type 1 (HIV-1) RNA and markers of immune activation were compared among HIV-1-infected female sex workers (FSWs) with (n=112) and without (n=88) sexually transmitted diseases (STDs) in Abidjan, Côte d'Ivoire. After adjustment for CD4+ T cells, the median virus load was 2.5-fold higher among HIV-seropositive FSWs with STDs than among those without an STD (P=.053). Median virus load was higher for FSWs with a genital ulcer (P=.052) or gonorrhoea (P=.058) than for FSWs without any STD. Median levels of markers of immune activation (CD38 and HLA-DR on CD8+ T cells, soluble tumor necrosis factor-alpha receptor II, and beta(2)-microglobulin) tended to be elevated, albeit nonsignificantly, among FSWs in the STD group. These findings have important public health implications in elaborating strategies for decreasing disease progression and transmission of HIV among FSWs.