Blockchain is mainstreaming, but the number of blockchain for development use-cases with proven success beyond the pilot stage remain relatively few. This paper outlines key blockchain concepts and implications in order to help policymakers reach realistic conclusions when considering its use. The paper surveys the broad landscape of blockchain for development to identify where the technology can optimise development impact and minimise harm. It subsequently critically examines four successful applications, including the World Food Programme’s Building Blocks, Oxfam’s UnBlocked Cash project, KfW’s TruBudget and Seso Global. As part of the on-going work co-ordinated by the OECD’s Blockchain Policy Centre, this paper asserts that post-COVID-19, Development Assistance Committee (DAC) donors and their development partners have a unique opportunity to shape blockchain’s implementation.