Book excerpt: While many effective interventions can reduce cancer risk, incidence, and death, as well as enhance quality of life, they are of no benefit if they cannot be delivered to those in need. In the face of increasingly dynamic and resource-constrained conditions, implementation science plays a critical role in delivering cancer control practices. This 30-page workbook was written by members of the NCI (National Cancer Institute) implementation Science team and reviewed by nearly 100 public health practitioners and implementation science researchers. Through summaries of key theories, methods, and models, the guide shows how greater use of implementation science can support the effective adoption of evidence-based interventions. Case studies illustrate how practitioners are successfully applying implementation science in their cancer control programs