On the afternoon of November 11, 2006, an outbreak with symptoms of diarrhea, vomiting, and fever occurred among the residents in elderly care center A in Taipei City. Bacterium anal swabs and fecal samples were collected from the 8 cases and 3 cooks who showed no symptoms and sent for further testing at Research and Diagnostics Center of the Centers for Disease Control. Among the 11 fecal samples, norovirus was found in 4 of which belonged to 2 residents and 2 care workers; thus showing a 36.3% positive rate in the testing. After preventive measures such as the isolation of the patients, disinfection of the environment and facilities, and the restriction of the personnel which were administered on the 15(superscript th) of November, no new cases occurred after the 19th of November. Further quarantine of patients stopped after the end of the outbreak on November 29.