This methodological guide will present how EU Statistics on crime and criminal justice are collected, which types of data are included and how they are classified in an international context. Furthermore, it will explain how data are processed and validated by Eurostat, how indicators are calculated, and what limitations exist. A significant part of this methodological guide is dedicated to the comparability of data. Which comparisons can be made, and which should be avoided, how different national definitions, legal systems and coverage impact comparability and why counting units and counting rules matter for comparisons. In short, this methodological guide will inform users of EU Statistics on crime and criminal justice how crime data can be interpreted and of the limitations in using administrative data when attempting to compare criminal activity between jurisdictions. Finally, it will present which products are available and where to find them on the Eurostat website.