Twenty-four patients with benign recurrent transient monocular blindness of possible migrainous etiology are presented. The visual loss was predominantly one-sided and stereotyped in character. Postural change or exercise was a provocative factor in half the cases. Other neurologic symptoms were not present and only one patient developed permanent visual loss during an attack. Evaluation by CT scanning, angiography, echocardiography, and ophthalmodynamometry, when performed, was uniformly normal.