Osteomyelitis is traditionally staged by the Waldvogel classification system. The Waldvogel classification is an etiologic system and does not readily lend itself to guiding surgical or antibiotic therapy. Other classifications have been developed to emphasize different clinical aspects of osteomyelitis. These classifications include those of Ger, Kelly, Weiland, Gordon, May, and Cierny-Mader. The Cierny-Mader classification is based on the anatomy of bone infection and the physiology of the host. The Cierny-Mader classification permits the development of comprehensive treatment guidelines for each stage. The Cierny-Mader classification is used to demonstrate the application of staging for the diagnosis and treatment of osteomyelitis.