The mortality of acute bacterial meningitis (BM) has remained stable in the last decades in spite of the use of new antibiotics, probably due to vascular complications. We report a 68-year-old woman with BM who had a malignant infarction of left middle cerebral artery territory 72 hours after admission to the hospital. The patient experienced a bad evolution and died four days after admission. The arterial involvement in patients with BM is explained by vasospasm of large arteries and vasculitis of small arteries. The medical treatment of a malignant middle cerebral artery infarct has a high mortality (Rev Méd Chile 2004; 132: 1217-20)