Although stigma is considered a major barrier to effective responses to the HIV/AIDS epidemic, stigma reduction efforts are relegated to the bottom of AIDS programme priorities. The complexity of HIV/AIDS-related stigma is often cited as a primary reason for the limited response to this pervasive phenomenon. In this paper, we systematically review the scientific literature on HIV/AIDS-related stigma to document the current state of research, identify gaps in the available evidence and highlight promising strategies to address stigma. We focus on the following key challenges: defining, measuring and reducing HIV/AIDS-related stigma as well as assessing the impact of stigma on the effectiveness of HIV prevention and treatment programmes. Based on the literature, we conclude by offering a set of recommendations that may represent important next steps in a multifaceted response to stigma in the HIV/AIDS epidemic.