We estimated the effect of Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participation in 1999 to 2000 on breastfeeding initiation and duration and well-child care. We applied multivariate regression to a sample of 2136 unmarried, low-income, urban mothers from the Fragile Families and Child Wellbeing Study. WIC participation was associated with small increases in the probabilities of initiating breastfeeding and having had at least 4 well-child visits since birth—behaviors that benefit infants beyond the newborn period—but not with breastfeeding duration.