Head Start includes family-oriented services to enhance parent-child relationships, but little is known about the effect of Head Start on parenting practices. Using data from the Early Childhood Longitudinal Study-Birth Cohort (n [is approximately equal to] 7000), we examined whether participation in Head Start was associated with maternal spanking, with particular attention to whether the association differed by child gender. We found that Head Start participation was associated with lower likelihood that mothers spanked their child in the past week at both preschool and kindergarten entry as well as lower likelihood that mothers would use spanking in a hypothetical situation, among boys but not girls. These beneficial effects of Head Start participation on mothers' use of spanking among boys were not reduced by additionally including maternal depression and child behavior problems. (author abstract)