This study aims to determine the HIV prevalence among female market vendors in St. Balikuddembe market and to investigate its association with vendors' characteristics and attitudes towards sexual relationships and practices in order to address the current gaps in HIV-prevention services in market communities. Market vendors engage in sexual risk taking and probably have HIV prevalence higher than the average for Uganda. Little is known about the attitudes towards sex and sexual behavior in this population. Knowing the HIV prevalence in this population, analyzing the association of HIV with the attitudes market vendors have towards sex and sexual practices will enhance HIV service delivery among vendors. HIV prevalence in female market vendors is higher than Uganda's national average and is driven by risky sexual behavior and permissive sexual attitudes. Vendors are a looming key population, thus any HIV reduction drive should include behavioral and attitude change component.