Managing natural infrastructure—forests, parks, green roofs, vegetated stormwater systems—is an integral part of sustainable urban water management. In Singapore, for example, the ABC (Active, Beautiful, Clean) Waters Programme promotes the use of natural infrastructure by building capacity in the public and private sectors and implementing pilot projects. Such an approach is not mainstream throughout Southeast Asian cities, and there remains important knowledge and implementation gaps that limit the potential of natural infrastructure for urban water management. In this talk, I will give an overview of the recent literature on natural infrastructure in Southeast Asia to highlight key implementation barriers. In addition to the geographic bias towards wealthier countries, I will show that current research and practice insufficiently considers long-term monitoring needs, climate change, and high levels of informality in Southeast Asian cities. Drawing on international experience, in particular Payment for Watershed Services programs, I will propose ways to address these barriers through action research on natural infrastructure in the region.