Purpose of the Review <p>Sexually transmitted infections (STIs) include a diverse set of bacteria, viruses, parasites, and other pathogens that can facilitate transmission of Human Immunodeficiency Virus (HIV). However, the extent to which STIs increase HIV risk and public health approaches to address this are still evolving.</p> Recent Findings <p>Compelling evidence suggests STIs increase the risk of HIV acquisition and transmission. STIs may lead to higher rates of HIV infection through multiple mechanisms including inflammation and disruption of the epithelium, facilitating immune cells which are targets of HIV, and increased viral load shedding in those that have HIV. While previous STI control efforts have shown mixed effectiveness in reducing HIV incidence, the success of doxycycline prophylaxis for preventing bacterial STIs offers a promising approach that may help prevent HIV at the population-level.</p> Summary <p>STIs significantly increase the risk of HIV acquisition and transmission. Increased understanding of public health approaches, which both contribute to STI control and also prevent HIV transmission, is needed.</p>