A case of potassium iodate toxicity in a 22-year-old man was reported. After taking a solution of highly concentrated potassium iodate, the patient developed nausea, vomiting, diarrhea and blurred vision. The visual acuity was hand motion in both eyes. The funduscopic examination showed retinal edema with subsequent pigmentary change at the macula and retinal pigment clumping resembling retinitis pigmentosa. The fundus fluorescein angiography and electrophysiologic studies showed degenerative changes of the retinal pigment epithelium and photoreceptor cells.