The revised Orthopaedic Trauma Association (OTA) Fracture and Dislocation Classification compendium republished in 2007 provides a complete system of fracture classification for all bones in the body that uses consistent methodology throughout the skeletal system. The 2007 OTA Fracture and Dislocation Classification has been established as the standard for the classification of fractures by OTA, AO, SociétéInternationale de Chirurgie Orthopédique et de Traumatologie (SICOT), the Journal of Orthopaedic Trauma, and many other organizations and publications and can now be recommended as the standard fracture classification for general use. Part I of this two-part series reviews the current OTA classification compendium, highlights its features, and describes the 2007 changes; part II provides examples of applying the classification to specific fractures.