A 5-month-old female infant, preterm, exclusively breast-fed, presented with a 2-month history of erythematous, erosive, and crusted patches and plaques in a peri-oral, scalp, genital, and peri-anal distribution. A clinical diagnosis of zinc deficiency was confirmed by a low serum zinc level in the infant and decreased maternal breast milk zinc. Complete resolution occurred within two weeks of oral zinc supplementation. Acquired zinc deficiency is a rare nutritional disorder of infants. Early diagnosis and adequate treatment will prevent associated morbidity and complications.