This is a guide to cities to improve “Food-Water-Energy Nexus” (FWEN) using green and blue infrastructure in cities. IFWEN is a new framework to address old problems in cities: unsustainable use and scarcity of natural resources, inefficient and wasteful management and social inequalities. FWEN is based on “systems thinking” instead of “silos thinking” to help integrate different sectors and departments in managing resources to improve efficiency and quality in the use of food, water and energy. By identifying the connections between these elements and the sectors involved in their governance, this guide adopts an “urban metabolism” approach. It outlines an integrated management vision in providing environmental services to its inhabitants. By considering the synergies and trade-offs between these resources within a collaborative governance approach, the methodology presented here can help urban managers and policy makers on the pathway toward sustainable development. Deployment of Green and Blue Infrastructure (GBI) can improve the FWEN. The FWEN approach addresses several of the Sustainable Development Goals (SDGs) simultaneously, particularly SDG 11 (Sustainable Cities and Communities), and supports the implementation of the 2030 Sustainable Development Agenda.