The Directorate-General for Library, Research and Documentation provides the three Courts of the European Union with the analytical and documentary support they require. Its activities are split between two directorates.

The Library Directorate manages a collection of works on European Union law, international law and comparative law, and on the national laws of all the Member States and certain non-member countries. That collection, together with the possibility to access many publications in electronic format, is, above all, a constantly updated tool, for use by the three Courts. External researchers may also access the collection. The Directorate's monitoring and cataloguing of legal materials results in bibliographic publications which contribute to its prestige.

The Research and Documentation Directorate is made up of lawyers from all the Member States and a team of documentalists. The comparative law studies that it produces enable the case-law to be informed directly by the legal traditions of the different Member States, which are the base on which the legal order of the European Union rests. In addition, the Directorate conducts thorough and in-depth analyses of the case-law of the three Courts with a two-fold objective:
- to enrich the European Court Reports of the Court of Justice and the Court of First Instance so as to facilitate their use;
- to supply information for electronic databases, some for internal use and others, accessible via the internet to any interested persons, which are useful tools for all lawyers dealing with European Union law.