A series of 116 patients with classic migraine were studied to record visual field defects. Thirty-four (29.3%) subjects had defects of the field of vision, 11 of them bilaterally, which made a total of 45 (19.4%) eyes. Downward isopter depression from above and contraction of the field of vision were the most common damages. A homonymous hemianopic defect was found in seven patients. The area of depressed vision helps to some extent in anatomical localization of the damage. Its etiology has not been fully clarified. The authors recommend more extensive clinical examinations of the visual field, i.e. follow-up of each patient with classic migraine by periodical testing of the field of vision.