Mucocutaneous infection with Candida in neonates ranges from such common conditions as thrush and diaper dermatitis to serious diseases with potential for systemic involvement, including congenital candidiasis and invasive fungal dermatitis. In premature infants, seemingly benign mucocutaneous involvement may precede systemic infection and thus warrants thoughtful attention. Skin involvement also may be seen as an expression of systemic disease. The physical appearance of these lesions is often characteristic, allowing easy diagnosis. The patients at risk differ by gestational age and postnatal age at presentation. Systemic candidiasis and invasive fungal dermatitis typically occur in premature infants, particularly those with extremely low birth weight (< or = 1,000 g), whereas thrush and diaper dermatitis may occur in infants of any gestational age or birth weight. Congenital candidiasis presents at birth, while invasive fungal dermatitis typically occurs within the first 2 weeks of life, and thrush, diaper dermatitis, and systemic candidiasis may occur at any time in infancy. Controversy exists concerning optimal therapy of mucocutaneous candidiasis.