Many youth who sell sex and adolescent men who have sex with men in sub-Saharan Africa are at high risk for HIV and other adverse health outcomes. However, these youth are often excluded from studies conducted with key populations in the region due to legal and ethical challenges. For example, the requirement to obtain parental consent for the participation of minors in research is often not safe or practical for youth whose sexual behaviors are stigmatized. This exclusion from research hinders the development and testing of interventions tailored for underage key populations. This project's long-term objective is to identify legal and ethical barriers to conducting HIV research with underage key populations in sub-Saharan Africa in order to inform strategies for overcoming these barriers to implement such research where it is feasible and warranted. The specific aims of this study are: (1) To examine the relationship between legal restrictions related to the participation of minors under the age of 18 in research and the implementation of studies including underage key populations (female sex workers and men who have sex with men) in 48 countries in sub-Saharan Africa. The content of each country's ethical and regulatory guidance on research with minors will be analyzed, and a systematic review of the literature on key populations in Africa will be conducted to determine where and what types of research (e.g., observational or therapeutic) have been conducted with underage key populations. (2) To assess through surveys the knowledge, attitudes and experiences of research ethics committee members and institutional review board members (n=419) in sub-Saharan Africa regarding the review of studies that include underage key populations as participants. We will analyze the country-level, committee-level, and individual- level characteristics associated with willingness to consider approving research with underage key populations. (3) To identify perceived obstacles to conducting research with underage key populations in Africa through surveys of two groups of researchers who have conducted studies with key populations in Africa: those who have a) included underage participants (n=50) and b) excluded underage participants (n=125). Deliberative focus group discussions will also be conducted with researchers and research ethics committee members. Findings will be disseminated to researchers, ethics committee members, and organizations representing youth and key populations in Africa.