The discovery of bovine spongiform encephalopathy (BSE) in Canada and the United States in 2003 prompted an immediate and decisive reaction from importers, with the closure of most markets to beef and cattle exports from Canada and the United States. Two years later, many of these bans have not been lifted or have been only partially lifted. These bans were put in place by national authorities attempting to protect the health of their citizens and may have been justified in the immediate period following the discoveries, but their long-term continuance is not supported by science. Trade regulations can be a powerful weapon in the fight against the spread of diseases and to protect health, but they can also unnecessarily restrict trade. Internationally agreed standards have been created in order to protect public health in the least trade restrictive manner. When dealing with BSE, however, the norm has been for countries’ regulations to be far more restrictive than those they have previously agreed upon internationally.