Little is known about how intermediaries called knowledge brokers work in low- and middle-income countries to help move evidence into policy and practice to improve health outcomes. The aim of this PhD research project was to understand how knowledge brokers spread and mobilize evidence in multiple countries and regions in the context of an internationally funded global health program. It used case studies, interviews, and surveys of nearly 600 health professionals in more than 65 countries. Findings show knowledge brokers participating in the studies worked in multiple roles in healthcare systems and used their professional networks to help policymakers, healthcare providers, and others adapt evidence for use in the local context. They exhibited attributes such as a “can-do” spirit to overcome challenges in implementing evidence. Knowledge brokers were influenced in selecting evidence by having an opportunity to share it during their professional duties, how well the evidence fit their professional role, successes in using the evidence in similar contexts, and how well it fit the healthcare decision-making culture of the country. Initiatives to increase evidence uptake should consider strengthening the use of knowledge brokers in health organizations and building their capacity to work across countries and regions.