The author has analyzed 54 cases of chronic subdural hematoma which were diagnosed by brain computerized tomography from March 1985 to February 1991. There were 49 men and 5 women. The common incidence of age was between fifth and sixth decades. Most of the cases(76%) had a history of head injury and nearly all cases complained headache(87%). All cases performed brain CT scan, which showed hypodense(37.1%), isodense(29.6%), hyperdense(14.8%) and mixed dense(18.5%) lesion. Of 54 cases, 34 cases were treated with craniotomy and membranectomy. 20 cases with burr-hole and drainage. There was no difference in results in both methods and most of the cases showed good postoperative course except 2 cases.