Over the course of 20 years of working with peace practitioners, CDA staff noticed that the many entities (organizations and individuals) working on an array of peacebuilding activities rarely managed to generate effective joint organizational efforts to achieve their shared peace goals. This concern was reflected in the book Adding Up to Peace: The Cumulative Impacts of Peace Programming, the “Framework for Collective Impact in Peacebuilding”, and four case studies on peacebuilding networks. This reflection paper provides more direct reporting on the conclusions and lessons learned from the case studies and consultations on collective impact by outlining common trends, challenges, and food for thought.