Erythropoietic protoporphyria (EPP), a recently described form of porphyria, often remains unrecognized. We report the case of a 7-year-old girl admitted for investigation of photosensitivity since the age of 18 months without any significant objective cutaneous lesions. Clinical features, quantitative determinations of porphyrins in blood, urine and stools, ferrochelatase activity and cutaneous histopathology helped to confirm the diagnosis of EPP. A familial study was also performed. The clinical, laboratory and genetic characteristics of EPP are reviewed.