Outbreaks of both infectious and noninfectious adverse events can occur in any healthcare setting and pose a threat to patient safety. Regardless of the scope of practice, an investigation of a potential outbreak involves certain epidemiological components. Cooperation between healthcare epidemiologists, infection preventionists, and public health experts is important in effectively managing outbreak responses in healthcare and community settings. The ultimate goal of any outbreak investigation is to identify probable contributing factors and to stop or reduce the risk for future occurrences.