Chronic sclerosing sialadenitis i.e. Küttner tumor is a rare inflammatory disease most commonly affecting the submandibular gland, due to clinical findings easily interpreted even as a malignant tumor. Our 45-year-old patient sought medical care due to a solid lump that had appeared under the right mandibular angle. The submandibular gland and associated hard mass were excised in a surgical operation conducted after the investigations. Histologic examination proved that the seldom diagnosed reactive Küttner tumor was in question.