We report the case of a 46 year-old woman presenting with unilateral postoperative visual loss after right frontal craniotomy for resection of an arteriovenous malformation in the supine position. The intraoperative course was uneventful with maintenance of hemodynamic stability. Blood loss was 300 ml; postoperative hemoglobin was 12.4 g/dl. In the recovery room, the patient reported loss of vision in her right eye. Ophthalmologic examination revealed decreased visual acuity, color vision, and visual field. Assessment of the retina was normal, but the patient showed a relative afferent pupillary defect consistent with the clinical diagnosis of ischemic optic neuropathy. Postoperative computer tomogram showed normal perfusion of ophthalmic artery and vein, no hemorrhage or signs of cerebral ischemia or edema. The patient recovered most of her vision 3 months after surgery. Anesthesiologists should be aware that this condition may follow uncomplicated intracranial surgeries in the supine position, and should obtain prompt ophthalmologic consultation when a patient develops postoperative visual loss.