Pre-trial detention (PTD) is an inherently problematic concept. Not only does it conflict with the right to liberty and the presumption of innocence but its use is associated with an extensive range of problems that affect pre-trial detainees, their families, the fair administration of criminal justice and wider society. Many of these problems have an EU dimension. Case law of the CJEU confirms, for example, that deficiencies in Member States’ PTD regimes threaten to undermine mutual trust and thus the effective functioning of mutual recognition instruments, such as the European arrest warrant (cf. the cases of Aranyosi and Caldararu). Against this background, the article examines the need for, and possible content of, EU PTD rules. It begins by summarising the problems that are associated with PTD and identifies their causal connection with deep-seated systematic practices and/or political and legal cultures at national level that tend to promote an over-reliance on PTD while serving to foment distrust in alternatives. Referring to the 2009 Roadmap for Strengthening Procedural Rights and other relevant texts, it is argued that EU action is necessary to address these deficiencies. This will provide the added value of enhancing justice, fairness and the overall effectiveness of legal and judicial systems, on the one hand, and strengthening the Area of Freedom, Security and Justice, on the other. The article then makes a number of proposals for the nature of such action, the most significant being that the EU should adopt a directive based on Art. 82(2) TFEU that establishes minimum rules relating to the use of PTD. This though would be insufficient in itself and should be complemented by a range of other measures that relate to the implementation of existing EU legislation and engagement in a variety of soft law actions. A detailed analysis of the content of these measures, including recommendations for the content of the mooted directive, is provided.