Significant investments are needed to support the global transition to a low-carbon, climate resilient future. Current finance flows fall short of global financing needs, and massive scaling up is needed to unlock additional financial resources and foster a sustainable investment pathway. Overcoming barriers to private sector investments is critical, and international climate finance can play a catalytic role in this regard. National development banks (NDBs) have a unique role in this context, both complementing and catalyzing private sector players. This publication discusses the unique role that NDBs could play in scaling up private financing for climate change mitigation projects through the intermediation of international and national public climate finance in their respective local credit markets and the conditions that would be needed for them to be most effective. It draws from experiences in international climate finance and best practices, processes, and products of NDBs within the Latin American and Caribbean region.