This document describes protocols and practices for ensuring the essential elements of a national stockpile of medical countermeasures for radiation emergencies, particularly of the pharmaceuticals required to treat radiation injuries. It also addresses governance and management of such stockpiles. It supersedes the 2007 WHO report on development of stockpiles for radiation emergencies, and includes updated information on some of the pharmaceutical elements of stockpiles and additional information on medicines recently approved in recent years for clinical management of radiation injuries in several countries. This publication was produced through the collaboration of a global network of experts and partners. We would like to thank them all for their support to WHO’s mission, thereby helping to increase global preparedness for radiological and nuclear emergencies.