Many millions of people around the world are affected by emergencies, the majority of whom are women and children. Among them are many who are known to be living with HIV and others who may not know their HIV status. In 2016, the World Health Organization (WHO) and United Nations Children’s Fund (UNICEF) published the Guideline: updates on HIV and infant feeding, where the relevance of these recommendations in emergencies was recognized. The purpose of this document is to provide operational guidance on HIV and infant feeding in emergencies. It is intended to be used to complement emergency and sectoral guidelines on health, nutrition and HIV, including specifically infant feeding, prevention of mother-to-child transmission of HIV and paediatric antiretroviral treatment. The envisaged target audience consists of decision-makers, policy-makers, national and subnational government managers and planners, managers of refugee camps and similar settlements for displaced persons, and managers and planners in United Nations agencies, nongovernmental organizations and other groups responding to humanitarian situations. This operational guidance is based on a consultation convened by the World Health Organization, the United Nations Children’s Fund and the Emergency Nutrition Network in Geneva in September 2016, which brought together a cross-section of senior-level participants from United Nations agencies, government, nongovernmental organizations, academia, and other agencies working in nutrition and HIV in emergencies. This document sets out basic principles related to HIV and infant feeding in emergency settings, and the actions that government and other stakeholders can take to prepare for emergencies.