Malignant lymphoma may occur in the oral cavity and oropharynx, but is most commonly located in Waldeyer's ring, particularly in the palatine and lingual tonsil. The occurrence of malignant lymphoma in the tongue is very rare. Clinical features are nonspecific ulcerative lesions that do not heal. In the literature, the majority of cases are non-Hodgkin’s lymphoma, diffuse large B cell type; however T-cell phenotype also may occur. We describe a 60-year-old man who presented with an ulcerative mass in the left lateral aspect of his tongue, unresponsive to medical therapy. After tissue biopsy, histopathological and immunohistochemical analyses confirmed a diagnosis of non-Hodgkin’s lymphoma, diffuse large B cell type.