Outbreaks of serogroup C meningococcal disease (SCMD) have been occurring more frequently in the United States since the early 1990s, and the use of vaccine to control these outbreaks has increased. These outbreaks are characterized by increased rates of disease among persons who may have a common organizational affiliation or who live in the same community. By using surveillance for SCMD and calculation of attack rates, public health officials can identify SCMD outbreaks and determine whether use of meningococcal vaccine is warranted. This report describes 10 steps for evaluation and management of suspected SCMD outbreaks. The principles described also apply to suspected outbreaks caused by meningococcal serogroups A, Y, and W-135. The effectiveness of mass chemoprophylaxis (administration of antibiotics to large populations) has not been demonstrated in most settings in which community and organizational outbreaks occur. However, in outbreaks involving small populations, administration of chemoprophylaxis to all persons within this group may be considered. The ability to validate some aspects of these recommendations is currently limited by incomplete reporting of serogroup information in most systems for meningococcal disease surveillance in the United States and by the relative rarity of SCMD and SCMD outbreaks.