In late 2002 a new disease, severe atypical respiratory syndrome (SARS), emerged in China. A hitherto unknown animal coronavirus (CoV) that had crossed the species barrier through close contact of humans with infected animals was identified as the etiological agent. It rapidly adapted to the new host and not only became readily transmissible between humans but also more pathogenic. Air travel spread it rapidly around the world and ultimately the virus infected 8096 people and caused 774 deaths in 26 countries on 5 continents. Aggressive quarantine measures successfully terminated the disease. Currently, there are no SARS cases recorded and most likely the virus no longer circulates in the human population. In this review we present an overview over SARS-Co virus biology, the disease and discuss strategies to develop antiviral drugs and vaccines.