Farmers’ varieties are a vital source of diversity in plant breeding. Much has been written about the development of sui generis regimes for the protection of plant varieties as an alternative to the dominant model of protection enshrined in the International Convention for the Protection of New Varieties of Plants (UPOV Convention).1 This chapter briefly discusses, first, the evolution of intellectual property protection in the area of plant varieties and, second, some of the fears that have been voiced over the years concerning the implications of plant variety protection (PVP) and plant patents, as well as some of the expectations about the benefits that could accrue to farmers through the development of sui generis forms of protection that cover farmers’ varieties. Against this backdrop, the chapter considers the main elements that may be present in sui generis regimes that depart from the model of the UPOV Convention, as illustrated by the sui generis systems adopted in India, Thailand and Malaysia as well as by the model legislation approved by the Organization of African Unity (OAU) in 2000. The requirements and other conditions of protection under these systems are examined, particularly as they apply to farmers’ varieties that do not comply with the uniformity or stability standards.