The establishment of intellectual property rights (IPRs) for plant varieties has caused considerable controversy, but there is relatively little empirical evidence on performance and options in developing countries. This paper summarizes the results of a recent five-country study, concentrating on the conduct of plant variety protection (PVP) regimes. It examines PVP in the context of other mechanisms that provide incentives for plant breeding. It discusses the principal options available to developing countries and examines the ability of PVP to offer protection from competing firms and from on-farm seed saving. It also looks at the administrative and management requirements of PVP regimes. Although the paper does not discuss patent protection for biotechnology it examines the IPR requirements for the introduction of transgenic varieties. Developing countries need to establish an appropriate PVP system, but PVP should be seen as part of a broader strategy for seed system development.