Since its foundation in the 1970’s, agroforestry science has evolved from setting its concepts, research approaches and flagship technologies towards its increasing contribution to ecologically sound land use, food security and income generation in the global North and South. The Third World Congress on Agroforestry held in Delhi in April 2014 continued contributed to this evolution by focusing, beyond the scientific realm, on the implementation of findings by convening ad-hoc stakeholders and subjects. Accordingly, some of the congress sessions dealt with key aspects of how agroforestry can foster and contribute to development. The special issue "Lessons for research, capacity development and policy in agroforestry for development" compiles approaches, experiences and overall lessons from (i) research, (ii) capacity development, and (iii) policy-making, capable to promote and generate developmental change through agroforestry. This introductory paper outlines the rationale for the three areas and the contributing articles.