Multiple myeloma (MM) is a neoplasia characterized by the proliferation of plasmacytoid cells, which produce abnormal immunoglobulins. It frequently creates local and systemic complications such as pathologic fractures and renal disease. This article reports the case of a 70-year-old man presenting a pathologic fracture of the right mandibular angle secondary to a plasmocytoma. He had a history of a previous pathologic fracture of the left mandibular angle 13 years before that was treated elsewhere, but no documentation was available. Investigation revealed the disease to be a MM and evolution led to renal failure and death. Differential diagnosis is necessary for this kind of pathologic presentation because MM presents a survival rate of 5.7% in 5 years and mandibular involvement happens in the advanced stage of the disease.