Lymphomas are malignant neoplasm of lymphocytes and their cell precursors. The two main forms of lymphomas are: Hodgkin’s lymphoma and Non-Hodgkin’s lymphoma (NHL). The NHLs are a heterogeneous group of neoplasms with Diffuse large B-cell lymphoma (DLBCL) being the most common variant of NHL. It is an aggressive lesion that can either develop de novo or as a transformation from a less aggressive form of lymphoma. In the oro-pharyngeal region, DLBCL usually involves Waldeyer’s ring (WR), paranasal sinuses, mandible and maxilla. Primary extra-nodal presentation of this entity within jawbones are rare and their initial manifestation is in the form of non-tender swelling. Other systemic symptoms may include night sweat, fever, and unexplained weight loss. Histopathologic evaluation together with immunophenotype and cytogenetic studies may reveal the histologic variant. Immunohistochemistry has an important role in distinguishing cell type and differential diagnosis. Treatment for primary extra-nodal lymphoma of the mandible typically consists of a combination of chemotherapy and radiotherapy. Proper evaluation and investigations are required for correct diagnosis so that patient may receive the treatment in early stage and attain good prognosis. Here we present a case of 48 year old male patient diagnosed with Diffuse B-cell lymphomaalong with its clinical, radiological, histopathological and immunohistochemical features.