Tuberculosis is a systemic disease with a world-wide distribution, and its occurance in the oral cavity is well documented in the literature. Disease of oral cavity and jaw caused by Mycobacterium tuberculosis is very rare, so it is often difficult to diagnose tuberculosis in the oral cavity. When granulomatous and ulcerative lesion persists in the oral cavity for a long time, it may be considered a tuberculosis. When differential diagnosis is needed, the most reliable indicators of mycobacterial infection are careful clinical evaluation, skin test, acid-fast staining, biopsy and culture. We report a case of tuberculous osteomyelitis which simultaneously occurred on the maxilla and mandible in a 85 years old man that proved diagnosis difficult, but which responded very well to surgical treatment and chemotherapy.