We report a case of systemic amyloidosis, with an unusual oral presentation, in a 70-year-old patient suffering from light chain myeloma. The patient presented with extensive ulceration of the tongue and alveolar ridges, and a large swelling in the floor of mouth. Incisional biopsies of the tongue and floor of mouth confirmed amyloid deposition within the tissues with evidence of necrotic ulceration. Amyloid deposition in the oral cavity usually manifests as macroglossia, however it can present elsewhere in the mouth as nodular or plaquelike lesions. Ulceration is a rare finding. This case highlights the variable nature of this condition, and how it can present a challenge to clinicians in terms of diagnosis and treatment.