Objectives: This study describes mothers who report spanking their infants in the first 13 months of life. Methods: Two hundred forty-six (246) mothers were interviewed in the Mother-Baby Unit of a large university-affiliated hospital in a large southeastern city of the United States. Ninety-three percent (93%) of those mothers were reinterviewed in their homes when infants were 6-13 months of age. Results: Younger mothers, those who endorsed fewer alternatives to corporal punishment, and those who experienced their infants as "difficult" were significantly more likely to spank their infants. Conclusions: The findings suggest the importance of more anticipatory guidance from physicians, nurses, social workers, and other professionals about discipline in the first few months of life, particularly given the risks associated with spanking infants and popular support for corporal punishment. (Contains 4 tables.)