It is a notable fact that in otolaryngologic and in stomatologic practice leukemic lesions are frequently misdiagnosed or their possible significance is entirely overlooked. In cases of acute leukemia the occurrence of a necrotic lesion on the inside of the cheek, a sore, enlarged or ulcerated tonsil, bleeding gums, acute stomatitis, epistaxis or rapidly developing cervical adenopathy is many times the first symptom of the disease. In cases of chronic leukemia the patient may have overlooked or made light of an enlarged spleen or liver, dyspnea, weakness, loss of weight and appetite or moderate fever but is driven to seek medical care by a prolonged hemorrhage after extraction of a tooth, bleeding of the gums, epistaxis, sudden deafness and vertigo or a disturbing lesion of the mouth or throat. The possibilities of these initial symptoms are well known to pathologists, hematologists and those internists who are consultants in