Acute arterial embolism continues to be a major cause of stroke morbidity in children and young adults. Potential therapy modalities include medical management and/or cerebral revascularization. The canine middle cerebral artery (MCA) was embolized by means of a pliable cylinder, 8 mm long by 1.6 mm in diameter, via the internal carotid artery. Control and experimental embolectomies were performed 6 hours following embolization. The experimental animals were treated with either dimethyl sulfoxide (DMSO) or methyl prednisolone. In the control animals, the average area of infarction in the brain was 1.45 cu cm. The animals treated with methyl prednisolone (2 mg/kg) or DMSO (2 gm/kg) showed no infarction of the brain, whereas methyl prednisolone (30 mg/kg) did not prevent infarction.