Objective: The objective was to identify key questions for emergency medicine (EM)-based adolescent sexual and reproductive health and to develop an evidence-based research agenda. Methods: We recruited national content experts to serve as advisory group members and used a modified Delphi technique to develop consensus around actionable research questions related to EM-based adolescent reproductive and sexual health care. Author subgroups conducted literature reviews and developed the initial list of research questions, which were iteratively refined with advisory members. External stakeholders then independently rated each item for its importance in expanding the evidence base (1 = not important to 5 = very important) via electronic survey. Results: Our final list of 24 research questions included items that intersected all sexual and reproductive health topics as well as questions specific to human immunodeficiency virus/sexually transmitted infections (HIV/STIs), pregnancy prevention, confidentiality/consent, public health, and barriers and facilitators to care. External stakeholders rated items related to HIV/STI, cost-effectiveness, brief intervention for sexual risk reduction, and implementation and dissemination as most important. Conclusions: We identified critical questions to inform EM-based adolescent sexual and reproductive health research. Because evidence-based care has potential to improve health outcomes while reducing costs associated with HIV/STI and unintended pregnancy, funders and researchers should consider increasing attention to these key questions.