Bovine spongiform encephalopathy (BSE) is one of several diseases known collectively as transmissible spongiform encephalopathies (TSE) and caused by prions, which are nonconventional infectious agents. The risk of human infection by exposure to a TSE agent is generally considered to be low, because of the species barrier. However, the prions causing BSE in cattle are able to cross the species barrier easily. The appearance of variant Creutzfeldt–Jakob disease (vCJD) after human exposure to BSE prions has highlighted the possible impacts of this infection on human health. Today, a major concern is that the number of BSE cases in many European countries, including the emerging eastern European countries of the EU, is growing. A further concern now emerging is the possibility that BSE could spread to other livestock species, such as sheep or goats. This paper provides an overview of BSE transmission and its potential implications for public health.