Objective: We set out to compare rates of breastfeeding between women who participated in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) with those of non-WIC mothers from 1978 to 2003.Methods: The Ross Laboratories Mothers Survey is a national survey designed to determine patterns of milk feeding during infancy. Mothers were asked to recall the type of milk fed to their infant in the hospital and during each month of age. Rates of breastfeeding in the hospital and at 6 months of age were evaluated. Logistic regression analyses identified significant predictors of breastfeeding in 2003.Results: From 1978 through 2003, rates for the initiation of breastfeeding among WIC participants lagged behind those of non-WIC mothers by an average of 23.6 +/- 4.4 percentage points. At 6 months of age, the gap between WIC participants and non-WIC mothers (mean: 16.3 +/- 3.1 percentage points) steadily increased from 1978 through 2003 and exceeded 20% by 1999. Demographic factors that were significant and positive predictors of breastfeeding initiation in 2003 included some college education, living in the western region of the United States, not participating in the WIC program, having an infant of normal birth weight, primipary, and not working outside the home. For mothers of infants 6 months of age, WIC status was the strongest determinant of breastfeeding: mothers who were not enrolled in the WIC program were more than twice as likely to breastfeed at 6 months of age than mothers who participated in the WIC program.Conclusions: Breastfeeding rates among WIC participants have lagged behind those of non-WIC mothers for the last 25 years. The Healthy People 2010 goals for breastfeeding will not be reached without intervention. Food package and programmatic changes are needed to make the incentives for breastfeeding greater for WIC participants.