Skin capacitance depends on the water content of the stratum corneum, and moisturizers have beneficial effects in atopic dermatitis. This study was performed to determine the skin capacitance in normal and atopic infants, and to evaluate the effects of different moisturizers on infantile atopic skin. The skin capacitance in 186 normal infants and 37 atopic infants was measured with a Moisture Checker. Measurements were also made for atopic infants after an application of pure petrolatum or an oil-in-water cream containing a humectant. Age-related decreases in skin capacitance were observed at the majority of dermal sites in normal infants. The skin capacitance was significantly lower in atopic infants compared with normal infants at all body sites. Pure petrolatum and oil-in-water creams containing humectants significantly augmented the capacitance from 2% to 7%. The reference values for skin capacitance may be helpful for delineating normal from atopic skin. Certain moisturizers can increase skin hydration.