This chapter deals with the origins of variety registration regulations, their implementation and their impacts on the use and improvement of farmers’ varieties. In this chapter, we document how variety registration systems have developed in Europe and the United States and how developing countries have adopted these models. Then we discuss how variety registration and sui generis models for the protection of plant varieties are linked. In addition, we discuss the operation of the current systems and how strict compulsory registration systems may outlaw the use, or at least the marketing, of the seeds from farmers’ varieties. We then examine attempts in Europe to correct this restriction and to merge the objectives of the seed and biodiversity policies. While these initiatives appear to have the potential for a positive impact on the use of farmers’ varieties, it is too early to assess their actual impact.