The twentieth century saw profound demographic changes, generating considerable anxiety about the well being of the child and the future of the family. The movement to ban corporal punishment provides a compelling example of how such anxiety is manifested in discussions of childrearing. Debates around child discipline speak directly to the burning question, "Who exactly is in charge of families today?" By and large, the common expert consensus is that corporal punishment is considered to be a symptom of dysfunctional parenting, yet corporal punishment is almost universal in American families, and especially prevalent in low-income and/or African American families. Single mothers in particular are believed to be at high risk for "harsh parenting," but family structure itself is closely tied to race and class. Most research regarding corporal punishment has relied heavily on white, middle-class samples, and very few studies have looked specifically at the relationship between family structure and corporal punishment. The study reported here is unique in that it offers and tests a conceptual model for predicting corporal punishment by family structure using a large sample of low-income, predominantly African American families and advanced analytical method. Study findings contradict commonly held beliefs regarding single mothers' propensity toward corporal punishment, as well as the reflexive equation of corporal punishment with harsh parenting. Mothers in this study were most likely to use (low level) corporal punishment when living with the biological father or in a multi-generational family. Likewise, maternal warmth was associated with (low level) corporal punishment. Mothers living with surrogate fathers were more likely to report higher, potentially problematic levels of physical punishment, consistent with research showing an elevated risk of child maltreatment in reconstituted families. This study demonstrates that family structure interacts in complex ways with race and class to influence parenting. Research that relies on main effects models of family structure and Eurocentric notions of family is likely to yield misleading findings and may indeed result in the denigration of legitimate cultural differences in parenting. Corporal Punishment and Low-Income Mothers is an essential, groundbreaking study with important implications for those in sociology and social work.