Description and evaluation of a case in which both occipital lobes of the brain and adjacent temporal and parietal areas were heavily damaged by malignant meningiomas. Loss of simple and complex visual functions resulted. During a 5-year period the clinical, neurologic, ophthalmologic, and psychologic findings could be completed by self-observation by the highly intelligent patient and compared with findings from three operations. Postmortal neuropathologic analysis showed loss of both left and right areas 17 and 18 and of right area 19. The localizations of elementary and complex visual functions in the brain are discussed.