This is a report of an outbreak of Pneumococcal pneumonia among nursing home residents in Tokyo, 2009. A total of 15 cases were identified, and their sputum culture grew Streptococcus pneumoniae, all of which were confirmed as serotype 11A and ST116. This outbreak ended through the implementation of strict contact precautions, education regarding the standard precautions among the staff, administration of prophylactic antibiotics to other asymptomatic residents, and vaccination. The fact that many cases were unvaccinated in this outbreak implies the importance of vaccination against S. pneumoniae among nursing home residents.