The current field of prevention science boasts an increasing armamentarium of effective preventive interventions, reflecting the growing promise of the field. However, we have yet to achieve significant scale with the most efficacious interventions, limiting the potential impact of prevention on population and public health. Further, there is considerable evidence that the goals of scale and quality often seem to work in opposition; implementation quality and fidelity suffer as preventive interventions increase in scale, potentially diminishing returns. As prevention science continues to mature, the growing arena of implementation science has accelerated the pace at which these challenges are being addressed. We believe the field has entered an important new era, reflected by the growing number and sophistication of systems, tools, and processes aimed at increasing scalability without sacrificing high-quality implementation. Many researchers and research teams are working in isolation to address this important challenge. It is our hope that the pace of advancement can be increased by promoting a broader discussion across many researchers, practitioners, and policy makers. This special issue of the Journal of Primary Prevention, focusing on measurement and monitoring systems and frameworks for assessing implementation and adaptation of prevention programs, offers some empirical examples that demonstrate the growth and development of prevention and implementation science and practice, as these fields move us closer to scalable systems and practices in applied contexts. The collection of articles in this special issue reflect the diversity of contexts in which these challenges are being addressed and the important underlying questions that must be answered as preventive interventions seek scale with quality.