A correlation study of CT and angiography was done in 100 patients who had clinical evidence of cerebrovascular occlusive diseases. 4-vessel cerebral angiography was done in all patients except 4 cases and clinical findings including the time of onset and etiology of vascular occlusion were not included in the evaluation. 81 aptients had positive CT findings and the lesions were most frequently found at middle cerebral artery (MCA) territory (40%), On angiography 63 patients had vascular occlusive lesions including 5 cases of venous thrombosis. MCA was the most frequent site of arterial involvement (57%) and followed by internal and/or vommon carotid (47%) and vertebro-basilar artery (12%) Poor correlation was obtained between CT and angigographic findings (Good 30% Fair 36%) and the lesions in branches made more positive result on CT(83%) than internal and/or common carotid lesions(54%) The degree of stenosis or time interval between CT and angiography had no role in the correlation. But good col-lateral circulation demonstrated on angiography significantly contributed to the negativity of CT finding.