This report reflects the main issues discussed during a workshop on “Preventive and Quiet Diplomacy, Dialogue Facilitation and Mediation – Best Practices from Regional Organizations 1” held in co-operation with the United Nations’ Department of Political Affairs in December 2010. The report identifies common challenges to mediation faced by regional organizations as well as good practices. Opportunities for closer co-operation among regional organizations on the issue of mediation support are also suggested.