This document provides guidance on the preparation, submission, and assessment of periodic safety update reports (PSURs) in the European Union. It describes the objectives, format, and content of PSURs, and provides further details on the submission of PSURs in the EU, including the list of EU reference dates and frequency of submission. It also covers the single EU assessment process for PSURs and quality systems related to PSURs at the level of marketing authorization holders, European Medicines Agency, and competent authorities in EU member states.