Tuberculosis is one of the major causes of ill health and death worldwide. It is a chronic granulomatous disease caused by various strains of Mycobacterium  tuberculosis. Tuberculosis lesions of the oral cavity are rare and can be  a diagnostic challenge. Most of the cases are secondary to pulmonary disease and the primary form is uncommon. Oral lesions of TB may be in the form of nodules, ulcers or elevated fissures. In this paper we present a case of primary oral tuberculosis affecting the gingiva manifesting as gingival enlargement in a 43 yr male patient. The diagnosis was  based on histopathologic examination , CBP, chest X–ray and immunologic investigation with  detection of antibodies against M.tuberculosis. This case report emphasizes the need for dentists to consider TB in the differential diagnosis of gingival enlargement keeping in view the increase in the incidence of tuberculosis