This study presents a synthesis that is an attempt to learn lessons from projects conducted by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS). These projects engaged with policy makers and other stakeholders by providing climate science and spaces for dialogue between researchers and decision makers for the purpose of improving climate change and agricultural policies. This study draws conclusions from across projects in five regions and confirms the presence of similar enablers to policy engagement and constraints to the use of scientific findings by policy makers in each region.