This webinar session addresses one overarching question: “How can an evidence-based intervention (EBI) be delivered with fidelity to its scientific components, while also responding effectively to changing real-word conditions?” Mindful of the public health adage, “one size doesn’t fit all,” how can intervention delivery staff respond effectively to these conflicting demands? This session will summarize major challenges and their resolution as illustrated by the “Fidelity-Adaptation Dilemma.” A general prevention science goal is to effectively disseminate, adopt, implement, improve, and sustain relevant EBIs to benefit residents from a local community. Strategies for addressing this dilemma across diverse real-world settings will be discussed.