A case of allergic urticaria due to erythritol is herein reported. A 24-year-old female presented with severe wheals over her whole body. The urticaria occurred after she had drunk a glass of canned milk-tea. When the cause of her skin reaction was examined, it was found that the drink contained erythritol; this was determined to have caused her urticaria. Erythritol has recently been used as an artificial sweetener in many kinds of foods and drinks because it contains no calories. Food and drink additives should thus be included in the differential diagnosis of allergic urticaria.