CT is very accurate in evaluating the location, size, shape and extension of acoustic neuroma, We analysed CTfindings of 23 acoustic neuromas seen at Department of Radiology, Kangnam St. Mary's Hospital, CatholoicUniversity Medical College during the period of from January 1981 to June 1987. 1. Five (22%) were men and 18(78%)were women with the high incidence occuring in the 4th and 5th decades. 2. Twenty two cases were diagnosedsatisfactorily by CT examinations which included axial, coronal and reconstruction images. One with the smallestdimension of 8mm in diameter could not be detected by the conventional CT scan. But it could be seen aftermetrizamide cisternography. Mean size of the tumor masses was estimated 3.6 cm in diameter. 3. The shape of thetumor was oval in 50%, round in 27% and lobulated in 23%. The masses were presented as hypodense in 50%, isodensein 32% and hyperdense in 18%. All tumors were extended from the internal acoustic canal toward thecerebellopontine angle. The internal acoustic canal was widened in 77%. Hydrocephalus was associated in 45%.Widening of cerbellopontine angle cistern was noted in 50%. 4. After contrast infusion the tumors were enhancedmarkedly in 45%, moderately in 32% and midly in 23%. The enhanced pattern was homogeneous in 41%, mixed in 41% andrim in 18%. The margin of the tumors was sharply defined in 82%. The tumors were attached to the petrous bone withacute angle in 73%. Cystic change within the tumor was found in 27%. The peritumoral edema was noted in 45%. Inconclusion, CT is one of most effective modalities to evaluate size, shape, extent and internal architecture ofacoustic neuroma as well as relationship with adjacent anatomic structures including the internal acoustic canal.