Computerized tomography (CT) of the brain has been available since 1973 and has changed neurological, neurosurgical and radiological practice beyond recognition. A rapid growth of literature has documented it role in the diagnosis of intracranial hematoma, cerebral atrophy, brain tumor, orbital lesions and postoperative tumor evaluation. This computerized method of image reconstruction is now also being applied to the rest of the body and to other diagnostic modalities such as isotopes and ultrasound. The initial impact of CT scanning in otolaryngology is largely in four areas: 1. Facial deformities either acquired or congenital as hypertelorism, fibrous dysplasia, ossifying fibroma and Crouzon's disease. 2. Tumors involving sinuses primarily or by secondary invasion. 3. Cerebello-pontine angle lesions as meningiomas, acoustic neuromas, and glomus jugulare tumors. The larger acoustic neuroma is well visualized by this technique rendering contrast myelography unnecessary. In CT scanning, subtle differences in position and an increase in density before contrast enhancement should allow a differentiation of angle meningiomas from acoustic neuromas; in addition, CT scanning has a very important role in the postoperative assessment of angle tumors. 4. Infections as cerebral abscess or cerebritis secondary to sinus or mastoid disease. The future holds changes that will allow much finer detail, re-orientation of the horizontal information into any plane, and much more accurate differentiation of tissue density. The principle of CT image reconstruction is being applied to both isotope and ultrasound scanning and should improve their accuracy and yield. If the rapid growth of the new technology over the past two years continues, even greater usefulness can be anticipated.