Clinical research involving osteomyelitis is difficult because of the multiple variables found in the disease process. In order to evaluate osteomyelitis critically, a more precise staging system is needed, along with reproducible animal models for each of the clinical stages. The current animal models for osteomyelitis include the rabbit models of Norden and Andriole, the rat model of Zak, and the dog models of Fitzgerald and Deysine. Although each animal model of osteomyelitis has certain advantages and limitations, they have provided us with a clearer understanding of this disease process and what forms of treatment may prove satisfactory.