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New strains of <i>Potato virus Y</i> (PVY) are adding to the challenges faced by seed potato certification officials across North America. The use of the traditional visual inspection to detect these new PVY strains has not been effective. This lack of effectiveness occurs because the new strains, which often cause milder symptoms in common North American varieties than the original PVY strains, are simply more difficult or even impossible to see. Poor visual detection has resulted in the certification of seed lots with high levels of PVY and has been contributing to a general increase in PVY throughout the continent. The history of PVY in the Idaho Certification system will be discussed as well as some of the reasons the virus has been on the increase over the last two decades. In response to steadily increasing levels of PVY in Idaho seed, the industry recently abandoned the increasingly ineffective visual inspections for PVY in favor of the laboratory-base ELISA test for determination of PVY during the winter seed grow out. This change has been responsible for a dramatic decrease in PVY in the Idaho Seed System and could prove to be a template for the entire North American seed potato industry.<p><p>Keywords: