This paper aims to identify progress and share countries’ learning on dealing with climate change and address the challenges climate change poses to social and economic development. It comes from collaboration between government development planners from countries in Asia and Africa who came together in series of meetings and workshops between 2011 and April 2013. A climate mainstreaming building blocks framework is outlined in this paper as a practical diagnostic for government officials to assess and plan the integration of climate resilience into their planning processes. The authors conclude that emerging trends within each building block indicate that countries are increasingly mainstreaming their integration efforts within existing development planning priorities and capacities. The building block framework aims to help governments to do this in a country-driven process that evolves from and is embedded in, existing development planning systems, capacity and priorities.