This review examines the categorization of Essentially Derived Varieties (EDV) introduced in the 1991 revision of the Convention of the Union internationale pour la protection des obtentions végétales (UPOV). Challenges in the implementation of the concept and progress made on a crop-by-crop basis to provide greater clarity and more efficient implementation are reviewed. The current approach to EDV remains valid provided i) clarity on thresholds can be achieved including through resource intensive research on an individual crop species basis and ii) that threshold clarity does not lead to perverse incentives to avoid detection of essential derivation. However, technological advances leading to new varieties resulting from the simultaneous introduction or change in expression of more than “a few” genes will so challenge the concept to require a new Convention. Revision could include deletion of the concept of essential derivation and revision on a crop-by-crop basis of the breeder exception. Countries that allow utility patents for individual plant varieties per se should consider removing that possibility unless plant breeders utilize those encouragements for risk taking and investment to broaden the germplasm base upon which the long-term sustainability of plant breeding resides.