Chapter 16 comparatively examines the national legislation in EU member states in order to reveal common patterns and differences in legal rules and their practical application with respect to gathering digital evidence for the purpose of criminal investigations. The study is essentially based on the information provided in the preceding book chapters, covering seven national legal systems selected for this research: Belgium, Estonia, Germany, Ireland, Luxembourg, Poland and Spain. The comparative analysis investigates not only the rules on access to digital evidence but also their broader legislative context. Indeed, before analysing how data can be obtained, it is important to understand the legal terminology and categorisations used in the different legal systems, as well as the national rules on data retention in light of the case law of the Court of Justice of the EU.