The author developed an original model of local cerebral ischemia using mongrel dogs. A left transorbital approach was used to occlude both the first segment of the middle cerebral artery(M1) and the common trunk of the anterior cerebral artery(A2). Histopathological examination revealed severe ischemic brain edema coinciding with severe neurological deficits within 3 days of the occlusion. Additionally, large cerebral infarcts involving the sensorimotor cortex were frequently found at 7 days. These infarcts were more extensive than those in cases with M1 occlusion alone.Fluorescein angiography and measurement of the local cerebral blood flow(l-CBF) demonstrated a filling defect of fluorescein in the gyri around the sylvian fissure coinciding with a 54% reduction of 1-CBF in the anterior sylvian gyrus after M1 occlusion. Additional occlusion of the A2 extended the filling defect zone to the coronal and sigmoid gyri, and lowered the 1-CBF further.The author believes that this model of cerebral ischemia is useful because one can alter the extent and duration of cerebral ischemia by the combination of occlusion or release of M1 and/or A2.