Rapidly spreading rhinocerebral infection by Phycomycetes (mucormycosis) in a diabetic patient with ketoacidosis is described. The dentist and dental specialists should be alert to the early signs and symptoms of this disease as they evaluate and follow patients who are debilitated and who have odontogenic pain. It cannot be overemphasized that a successful outcome is critically dependent on early recognition and prompt therapy, especially in a person with diabetic acidosis as death may occur within 2-5 days after the first symptoms appear.