This document represents the World Health Organization Operational framework for building climate-resilient and low-carbon health systems. The framework aims to increase the resilience of health systems to climate change in order to protect and improve the health of communities in an unstable and changing climate, while optimizing resource use and implementing strategies to reduce greenhouse gas emissions. It aims to contribute to the design of transformative health systems that can provide safe and quality care in a changing climate.  Implementing the ten components of the framework would help health organizations, agencies, and programs better anticipate, prevent, prepare for, and manage climate-related health risks, thereby reducing the burden of associated climate-sensitive health outcomes. Implementing low-carbon health practices would contribute to climate change mitigation while improving health outcomes. Achieving these goals is an important contribution to universal health coverage (UHC), global health security, and the specific targets under the Sustainable Development Goals (SDGs). The document is a useful resource for decision-makers in health systems, including public health agencies and other specialized institutions, as well as decision-makers in sectors that determine health.