Successful capacity for greening development depends to a large extent on sustained support from development support providers. This chapter examines what capacities these providers themselves need at the levels of the enabling environment, the organisation and the individual in order to effectively assist countries in building their own environmental capacities. It addresses inter-agency co-operation and provides examples of best practice. It examines how development support providers can themselves assess their existing capacity to deliver assistance and how they can strengthen their capacities for effective future support delivery. A self-assessment tool is included to help development support providers evaluate their capacity requirements.