1. 1. A case of multiple myeloma, plasma-cell type, is reported, with the largest lesion and the first to produce symptoms, located in the mandible. 2. 2. Dentists may be the first to discover the lesions of multiple myeloma. 3. 3. The lesion of the right side of the mandible was removed in mass and the pathological fracture controlled by the extraoral fixation and roentgen therapy, enucleation of the tumor mass, followed by roentgen treatment, allowed sufficient osteogenesis to permit the removal of the splint and to provide a comfortable, functioning jaw for the remainder of the patient's life. 4. 4. Bence-Jones protein did not appear in the urine until after the appearance of the lesions in the long bones, approximately four months before death.