Key Points A new infectious disease, called severe acute respiratory syndrome (SARS), appeared in southern China in 2002. During the period from November 2002 to the summer of 2003, the World Health Organization recorded 8098 probable SARS cases and 774 deaths in 29 countries. A previously unknown coronavirus was isolated from FRhK-4 and Vero E6 cells inoculated with clinical specimens from patients. A virus with close homology to SARS-CoV was isolated from palm civets and racoon dogs, which are used as food in southern China In less than a month from the first indication that a coronavirus might be implicated in the disease, the nucleotide sequence of the virus was available, and diagnostic tests were set up. The phylogenetic analysis of the SARS-CoV genome revealed that the virus is distinct from the three known groups of coronaviruses and represents an early split-off from group 2. The development of antiviral drugs or vaccines is being investigated. Viral enzymes essential for virus replication, such as the RNA-dependent RNA polymerase (RdRp), the 3C-like cystein protease (3Clpro) and the helicases are the most attractive targets for antiviral molecules. Of the possible vaccine targets, the spike (S) protein represents the most promising one. So far, β-interferon is the only licensed drug available, which has been reported to interfere with virus replication in vitro. Should SARS return during the next winter, we will still need to rely mostly on quarantine measures to contain it.