The Communicable Diseases Network Australia guidelines provide information for early clinical and public health management of meningococcal disease, including community outbreaks. While community outbreaks of meningococcal serogroup C infections have been reported, community outbreaks of meningococcal serogroup B infections have not been declared in Australia. Three cases of meningococcal serogroup B disease occurred in 2 adjacent suburbs in western Sydney in Spring 2008. Although the temporal and geographic proximity of these cases fulfilled the criteria for a community outbreak, difficulties in establishing an epidemiological or serosubgroup link, and arbitrary definition of the term 'community' provide challenges for identifying such outbreaks. In addition, the declaration of a community outbreak of meningococcal B infection does not provide guidance for the public health response because a vaccine is not available and community-wide prophylaxis is not recommended.