The Singapore Ministry of Health (MOH), with assistance from the World Health Organization (WHO), has been investigating an outbreak of severe acute respiratory syndrome (SARS). This is a novel condition caused by the SARS-associated coronavirus (SARS-CoV) and is characterized by both an atypical pneumonia and efficient nosocomial transmission. This report summarizes epidemiologic features of this outbreak in Singapore, including the influence of super spreaders and the national prevention and control strategy.