Hydroa vacciniforme is a very rare photosensitivity disorder. The primary skin lesion is a vesicle or bulla which then heals with vacciniform scarring. We report a case of hydroa vacciniforme recurred after 3 years period of quiescence in a 20 year-old man who had had history of the disease from the age of two. The duplication of the natural lesion, clinically and histologically, was successfully made by artificial UV-A irradiation on the patient's back.