CHAI’s Demand-Driven Evaluations for Decisions (3DE) program is a pioneering approach to support ministries in the health sector with evidence-based decision-making by using rigorous impact evaluations in a demand-driven, rapid, and efficient way. The 3DE program has complied a manual describing the lessons learned from the 3DE pilot program. This manual is not meant to be a comprehensive evaluation guide; rather, it aims to focus on the particularly innovative and unique aspects of 3DE, including the demand-driven nature of the evaluation questions, the maintained policy relevance in implementation, and the use of results to inform policy change.