Sensory neuroophthalmic abnormalities due to cerebral lupus erythematosus, with involvement of visual pathways posterior to the optic chiasm, occurred in 12 patients with systemic lupus erythematosus. Five underwent detailed evaluation because of an hallucination, 4 for visual loss, and 3 for both. Hallucinations were either unformed (for example, bright lights, straight lines) or highly formed (for example, faces), in which case they were invariably recognized by the patient as inappropriate. In no instance did they occur in association with delirium, confusion, or use of hallucinogenic drugs. Patients with loss of vision had scotomas, homonymous field defects, and cortical blindness. These features indicate disease in the posterior cerebral artery circulation, a localization often supported by ancillary neurologic findings, for example, vocal cord paralysis, diminished gag reflex. Thus, various visual dysfunctions may occur in systemic lupus erythematosus due to cerebral vasculitis. At times they may be the most prominent and disabling feature of the disorder.