Acute macular neuroretinopathy is a rare, unilateral, or bilateral condition of abrupt onset causing parafoveal scotomata and occasionally reduced visual acuity. The features are described in five new cases, and the evolution of the lesions described over a period of 9 months to 9 years. One patient was studied by fine matrix perimetry, which indicated a generalized elevation of thresholds at the macula early in the disorder, together with parafoveal scotomata. The thresholds improved over several months, and the scotomata became less dense. In another case, the scotomata were still present at 9 years, although at this time they were less dense. The condition appears to mainly affect young women, and in this group there is a high incidence of a recent immunologic disturbance suggesting an immune-based etiology.