Acrodermatitis enteropathica (AE) is a rare autosomal recessive disorder of early infancy, and is characterized by periorificial dermatitis, alopecia, and intractable diarrhea. Serum zinc levels are usually low in untreated patients and the oral administration of zinc sulfate can clear skin lesions and other symptoms. Although premature and cow's milk-fed infants are at particular risk of developing AE, there have been a few reports about AE in term and breast-fed infants. We report a case of transient AE in a 4-month-old breast-fed infant. This patient suffered from diarrhea and dermatitis for more than a month. Her skin lesions were erythematous, scaly, crusted, psoriasiform, eczematous, with an eruption at the chin, and a periorificial disposition with involvement of the flexural areas of lower extremities. Her serum zinc level was almost normal at 129 µg/dL (reference range: 60-121 µg/dL), but the zinc level in her hair was low: 8 mg percent (reference range: 10-21 mg percent). Skin biopsy findings were consistent with AE. Seven days after zinc supplementation, the skin lesions and diarrhea improved. The authors recommend that a clinical trial of zinc supplementation be considered in cases where there are suspicious of AE, even when the serum zinc level is normal.