Two young women noted acutely altered vision while suffering an adverse reaction to an intravenous injection of contrast agent for computerized tomography. One patient initially showed swollen maculas with subtle opacification of the parafoveal retina. Deep retinal lesions typical of acute macular neuroretinopathy were present later in both cases. Paracentral scotomas corresponding to the fundus lesions were present in both patients but subsequently improved. The temporal relationship of the onset of symptoms and the retinal abnormalities to the adverse reaction suggests that acute macular neuroretinopathy in these patients was caused either by the adverse reaction or its treatment.