Principle 10 of the Rio Declaration provides for the three ‘pillars’ of environmental democracy, that is, the right of the public to obtain environmental information, to participate in environmental decision-making procedures, and to have access to justice in environmental matters. This chapter deals with some key issues concerning the third pillar’s rights on access to justice. First, it covers the relevant historical background and outlines developments in international law in this area. Following on from setting the context, access to justice in different regional human rights conventions is discussed in respect of their strengths and shortcomings. Although there has been a significant ‘greening’ of the provisions therein relating to the protection of family and home, as well as the requirement for a fair trial, most of these conventions are confined to ‘individual’s rights’ in a more traditional sense. As for the protection of general environmental interests, the international human rights instruments remain far less effective. Instead, the most advanced instrument on environmental democracy currently is the regional 1998 Aarhus Convention from UNECE with 47 signatory Parties. Under Article 9 of this Convention, the public is entitled to have access to justice to challenge refusals to make environmental information accessible, decisions and omissions about permits for large installations and operations which may have a significant impact on the environment, as well as other kinds of activities which may breach environmental legislation. These provisions and their implementation in EU law are analysed, using recommendations from the Aarhus Compliance Committee and case-law of the Court of Justice of the European Union (CJEU) as sources of interpretation. The main focus is on standing for individuals and environmental non-governmental organizations (ENGOs), the requirement for a review on both substantive and procedural legality, the effectiveness of the review procedure and costs. The chapter concludes with a short note on future prospects for access to justice for the public concerned in order to protect a healthy environment, on a more regional and global level.