Implementation science is a multidisciplinary field that focuses on studying and promoting effective strategies for translating evidence-based interventions (EBIs) into routine practice to improve outcomes in real-world settings. It has been increasingly used to document and assess interventions, as it helps to make sense of how, when, where, and why research results and EBI are, or are not, being successfully used. When compared to traditional project design, implementation, and management of health care interventions, implementation science can add value by addressing the specific complexities and challenges associated with implementing and scaling up these interventions. More specifically, it helps to analyze and understand the contextual factors, stakeholder dynamics, and system-level barriers that can hinder the successful adoption and integration of health care interventions. In this sense, by integrating implementation science principles the World Bank can tailor strategies, develop robust implementation plans, and leverage evidence-based practices to overcome implementation problems, which is particularly useful for primary health care interventions and other interventions targeted at improving health and nutrition outcomes at scale. It is important to consider implementation strategies that are responsive to context, as they help bridge the gap between EBI and implementation outcomes. Tailoring implementation strategies to the specific context enables implementers and managers to address barriers and leverage facilitators, thereby increasing the likelihood of success.