STDs and sexual network patterns have emerged as major proximate determinants of HIVtransmission among African Americans. Mounting evidence suggests that the convergence of structural and contextual factors, socio-cultural factors, and individual-level behaviors and risk factors, play a critical role in heterosexual HIV transmission among African American women. However, the dynamics of the relationship between these myriad factors remain unclear. This study will conduct a cross-sectional study of 500 African American women in two NorthCarolina counties with high rates of sexually transmitted diseases and HIV to examine risk factors for these infections. Specifically, we will determine the prevalence of Neisseriae gonorrhoeae (GC), Chlamydia trachomatis (CT), and HIV and estimate HIV incidence. In particular, we aim to increase our understanding of socio-cultural factors (for example, religiosity and spirituality) and proximate determinants (e.g., epidemiologic factors and high-risk sexual behaviors and practices, such as concurrent partnerships) that influence HIV/STI transmission and determine the strength of their association with GC, CT, and HIV infection. We will also conduct qualitative research through focus groups among 70-80 African American women to obtain more in- depth understanding of socio-cultural, structural, socioeconomic, and other contextual factorsthat influence HIV transmission among African American women in the study population; and behavioral and other proximate determinants identified as important in the cross-sectional study. Understanding these factors is a critical first step in designing effective HIV interventions for this population. Lay Language: This study is relevant to public health because it will examine risk factors for sexually transmitted diseases and HIV among African American women in two North Carolina counties with high rates of these infections. The goal of this study is to increase our understanding of how socio-cultural factors such as religion; socio- economic factors such as neighborhood poverty and racism; and other environmental factors such as a lack of recreation influence HIV transmission in this area.