The unique structure, role and operations of government high-security (HS) laboratories which work on animal diseases are described, with particular reference to the laboratories of nine countries. High-security laboratories provide cost-effective insurance against catastrophic losses which could occur following exotic disease outbreaks. The importance of these laboratories is reflected in the fact that several new laboratories have recently been constructed at considerable expense and older facilities have undergone major renovations. Biosecurity is fundamental to the operation of high-security laboratories, so good facility design and microbiological security practices are very important. High-security laboratories conduct exotic disease diagnosis, certification and surveillance, and also perform research into virology, disease pathogenesis and improvements to diagnostic tests and vaccines. The mandate of these laboratories includes the training of veterinarians in the recognition of exotic diseases. One extremely important role is the provision of expert advice on exotic diseases and participation (both nationally and internationally) in policy decisions regarding animal disease issues.