Systemic innovation must be the driving force behind actions to transform cities to address climate change. It includes transformations of environmental, social, economic, financial, technical, regulatory, and governance nature, supporting the permanent change of cities. Nature-Based Solutions (NBS), can be part of the tools to address the challenges ahead. This research aims to define a framework of action in cities for the implementation of NBS, demonstrating the importance of quantifying its benefits in environmental and socio-economic terms, to boost public policy design and investment in this field. This work is divided into two parts. The first part, analyses some of the European measures in the field of sustainable development in cities, focusing the research on the case of Madrid. And in the second part, some case studies are presented to reflect the measures and actions taken to promote the implementation of NBS in the city of Madrid. As a result, the potential levers of change for the implementation of NBS are identified, highlighting the importance of quantifying their effects to demonstrate the potential value that can be generated within cities.