Terson's syndrome refers to the occurrence of vitreous hemorrhage with subarachnoid hemorrhage (SAH), usually due to a ruptured cerebral aneurysm. Although it is a well-described entity in the ophthalmological literature, it has been only rarely commented upon in the neurosurgical discussion of SAH. Fundus findings are reported in a prospective study of 22 consecutive patients with a computerized tomography- or lumbar puncture-proven diagnosis of SAH. Six of these patients had intraocular hemorrhage on initial examination. In four patients vitreous hemorrhage was evident on presentation (six of eight eyes). In the subsequent 12 days, vitreous hemorrhage developed in the additional two patients (three of four eyes) due to breakthrough bleeding from the original subhyaloid hemorrhages. The initial amount of intraocular hemorrhage did not correlate with the severity of SAH. Two of the six patients with intraocular hemorrhage died, whereas five of the 16 remaining SAH patients without intraocular hemorrhage died. Of the four survivors with intraocular hemorrhage, three showed gradual but significant improvement in their visual acuity by 6 months. The fourth underwent vitrectomy at 8 months after presentation and had a good visual result. With modern and aggressive medical and microsurgical management, Terson's syndrome should be recognized as an important reversible cause of blindness in patients surviving SAH.