This Guide suggests how the Health Cluster lead agency, coordinator and partners can work together during a humanitarian crisis (emergencies or disasters) to achieve the aims of reducing avoidable mortality, morbidity and disability, and restoring the delivery of and equitable access to preventive and curative health care as quickly as possible. It highlights key principles of humanitarian health action and how coordination and joint efforts can increase the effectiveness and efficiency of health interventions. Although addressed to Health Cluster lead agencies, coordinators and partners, the guidance is equally valid for coordinators and members of health sector coordination groups that seek to achieve effective coordinated health action where the Cluster Approach has not been formally adopted. Search keywords: earthquake, disaster.