[en] The aim of this publication is to provide practical guidance for public information officers on the preparation for and response to a nuclear or radiological emergency, and to fulfil in part functions assigned to the IAEA in the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (Assistance Convention), as well as meeting requirements stated in IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles, and in IAEA Safety Standards No. GS-R-2, Preparedness and Response for a Nuclear or Radiological Emergency. Under Article 5(a)(ii) of the Assistance Convention, one function of the IAEA is to collect and disseminate to States Parties and Member States information concerning methodologies, techniques and results of research relating to response to nuclear or radiological emergencies. IAEA Safety Standards Series No. GS-R-2 establishes the requirements for an adequate level of preparedness for and response to a nuclear or radiological emergency in any State, and specifies that 'All practicable steps shall be taken to provide the public with useful, timely, truthful, consistent and appropriate information throughout a nuclear or radiological emergency' in the response phase. It also requires 'responding to incorrect information and rumours; and responding to requests for information from the public and from the news and information media'. This publication provides guidance in the form of action guides and information sheets that can be easily applied by a State to build a basic capability to respond to a nuclear or radiological emergency. This guidance should be adapted to fit the user State's organizational arrangements, language, terminology, concept of operation and capabilities. This publication is published as part of the IAEA's Emergency Preparedness and Response series and complements the Manual for First Responders to a Radiological Emergency in the parts related to the tasks of public information officers. It takes account of the lessons learned from past emergencies, including the accident at TEPCO's Fukushima Daiichi Nuclear Power Station in 2011, and from research, while ensuring consistency with IAEA Safety Standards Series No. GS-R-2.