The classification of a disease is considered as a mandatory step so as to properly understand its various presentations. This also aids to formulate a favourable management plan best suited for the patient. Attributing to this fact, various researchers have proposed different classification systems of osteomyelitis in the literature. These different classification systems are based on Anatomic position, Clinical presentation, Pathological features or Radiological features of the disease. Some of the authors have even classified osteomyelitis on the basis of etiology and pathogenesis too. Henceforth there are multiple classification systems of osteomyelitis of the jaws throughout the literature. Authors also believe that these multiple classification systems has created confusion and hindered the comparative studies for the same. This in turn affects the pertinent management. This particular chapter highlights various classification systems of osteomyelitis of jaws.