Observing the gap between the need for low-emission, climate-resilient investment and current project finance outlays, a high-level group of public and private organizations and governments launched in September 2014 the Cities Climate Finance Leadership Alliance (CCFLA), a coalition of cities, banks, national governments and civil society organizations with the aim of accelerating and scaling up climaterelated finance for the world’s cities. The group agreed that to improve capital flows, one needs to have an effective way to measure them. This inaugural CCFLA report – facilitated by the Executive Office of the Secretary-General’s (EOSG) Climate Change Support Team (CCST) – is the first attempt to develop a systematic global assessment of the urban climate finance sector. The report provides an overview of the current challenges to financing and the solutions needed. Through this inaugural publication, we note the need to gather more data on climate-related finance flows to cities. This report also highlights the critical steps required to accelerate and scale up financing, accumulate more data on climate related finance flows to cities, and the innovative tools and instruments that can be replicated and scaled.