We used fasting diet therapy with a 28-year-old woman with chronic urticaria who responded only to systemic administration of glucocorticosteroids. The rashes began to decrease on the third therapeutic day and completely disappeared on the 11th day. Although the eruptions relapsed three days after the termination of the therapy, they were milder than previous ones. We also discussed the possible efficacy of fasting diet therapy for chronic urticaria as reported in the literature.