Gender mainstreaming, with its promise of gender transformation, equality and empowerment, has become a central pillar of development discourse, policy and practice. Yet, the implementation of these promises has largely been disappointing. Proposed ‘solutions’ have brought little new to the table. This article suggests that we need to rethink the link between policy and implementation, recognising that both are political processes and that while policies set agendas, both policies and their implementation are deeply influenced by societal factors. Drawing on critical development analysis and feminist writings, the article explores the transformative potential of gender mainstreaming in international development organisations in an increasingly complex, unequal and gendered world. Copyright © 2013 John Wiley & Sons, Ltd.