We report a patient with severe ethylene glycol poisoning initially mimicking acute basilar artery occlusion and elucidate the importance of immediate diagnosis and treatment: a previously healthy 59-year-old truck driver presenting with hallmarks of basilar artery syndrome after having consumed an unknown substance. Immediate application of intravenous ethanol and hemodialysis could not prevent the development of a malignant brain edema within hours. This report describes a new clinical presentation of severe ethylene glycol intoxication mimicking acute basilar artery occlusion with the development of a fatal brain edema within hours, despite adequate treatment.