A group of basic scientists, clinicians, clinical investigators, psychologists, patient advocacy groups, and representatives from professional societies and governmental agencies met at the National Institutes of Health in October, 2007 with the long-term goal of having the menstrual cycle accepted and understood as a marker of general health in adolescent girls. An equally important goal was to develop a research agenda for this area of investigation. This chapter comprises the highlights of discussions throughout that meeting, with an emphasis on ideas generated during a final session led by an internationally renowned physician–scientist, in which reports from four breakout groups were presented. The specific goal assigned to each group was to develop an agenda that would set the stage for how research should be conducted over the next 100 years, and to identify the pressing research questions that should be addressed related to the menstrual cycle and adolescent health. The four research areas represented in discussion groups included: emotional health; genetics; metabolism and reproduction; and the promotion of conduct of clinical research. Insights are also provided by five clinical investigators, including two outside experts, on topics of priority for a research agenda in the area of adolescent reproductive health, as well as how the research itself should be conducted.