Cases of Legionnaires’ disease reported to the CDC have increased dramatically. The causes of this increase will be discussed as well as the current status of national and international guidelines and standards. Environmental culturing of water systems for Legionella is crucial for both the investigation of Legionella outbreaks and routine microbiological surveillance for Legionella. Despite its importance in prevention strategies, there is a lack of standardization of environmental monitoring techniques for Legionella spp. Culture remains the “gold standard” used for detecting Legionella; however numerous “rapid” methods are being used. Sensitivity and specificity of the various environmental testing methods will be reviewed as well as sample collection, processing, hold time and interpretation criteria.