The Basel Institute on Governance and its International Centre for Collective Action (ICCA) hosted an international conference on anti-corruption Collective Action with almost 200 participants from the private sector, government, international organisations and civil society. The conference took place on October 20-21, 2016 in Basel and was part of the B20 efforts to promote Collective Action in anti-corruption.  This year’s edition was organized under the theme Collective Action: Evidence, Experience and Impact and aimed principally at drawing lessons from Collective Action initiatives from around the world as well as dedicated research in relation to the usefulness for companies of Collective Action to more effectively prevent and resist bribery and extortion. The conference report, now online, summarizes the main proceedings and findings from the event, addressing the latest research and practice in the field.