The authors had observed a rare case of osteopetrosis from 8 years old male who had complained nasal obstruction at, Department of Dental Radiology, Kyung Hee University. In the serial roentgenograms the following results were revealed. 1. This osteopetrosis was considered to be malignant rather than benign. 2. In the skull, the greatest degree of radiopacity was found in the base. The pituitary fossa appeared to be small and posterior clinoid process revealed clubbing and thickening. 3. In the frontal and nasal bones were slightly enlarged with marked radiopacity and paranasal sinuses were obscured. 4. The maxilla was markedly affected and bony trabeculae were seen to be coarse and thickened but mandibular posterior segment slightly. 5. There were long retardation of the tooth eruption and physiologic resorption of the deciduous teeth, and tooth root revealed stunted and dwarfed appearance in the both jaws. 6. In this case, the thickened alveolar lamina dura was indistinguishable.