This report presents the EU legislation on the marketing of seed and plant propagating material, with a particular view to how it affects agricultural biodiversity. The main principles of the EU’s 12 basic directives in this area and the three directives providing derogations for the purpose of conservation and sustainable use of plant genetic resources for food and agriculture are discussed. As this part of EU legislation is currently undergoing review, the various elements of the review process are also presented. In addition, the report contains a guide to the literature on the development of such legislation in Europe, its effects on agricultural biodiversity, and the content and consequences of the EU directive that provides derogations for conservation varieties.