PURPOSE: To conduct an expert-led process for identifying research priorities for eight areas of adolescent health in low- and middle-income countries. Specific adolescent health areas included communicable diseases prevention and management, injuries and violence, mental health, noncommunicable diseases management, nutrition, physical activity, substance use, and health policy. METHODS: We used a modified version of the Child Health and Nutrition Research Initiative methodology for reaching consensus on research priorities. In a three phase process, we (1) identified research and program experts with wide-ranging backgrounds and experiences from all geographic regions through systematic searches and key informants; (2) invited these experts to propose research questions related to descriptive epidemiology, interventions (discovery, development/testing, and delivery/implementation), and health policy/systems; and (3) asked the experts to prioritize the research questions based on five criteria: clarity, answerability, importance or impact, implementation, and equity. RESULTS: A total of 142 experts submitted 512 questions which were edited and reduced to 303 for scoring. Overall, the types of the top 10 research questions in each of the eight health areas included descriptive epidemiology (26%), interventions: discovery (11%), development/testing (25%), delivery (33%), and policy, health and social systems (5%). Across health areas, the top questions highlighted integration of health services, vulnerable populations, and different health platforms (such as primary care, schools, families/parents, and interactive media). CONCLUSIONS: Priority questions have been identified for research in eight key areas of adolescent health in low- and middle-income countries. These expert-generated questions may be used by donors, program managers, and researchers to prioritize and stimulate research in adolescent health.