Positive health outcomes, such as reduced chronic and acute illnesses for mother and infant have been associated with increased duration and exclusivity of breastfeeding and will benefit families and society as a whole. The numbers of low-income women (those participating in WIC programs) who were breastfeeding at discharge, 6 months and 12 months post-partum in 1997 were far below the goals recommended by Healthy People 2010 and professional organizations. Low-income women have identified lack of social support as are mark able barrier to sustaining exclusive breastfeeding. Research identifies several social support interventions that have shown increased breastfeeding duration in low-income women, however none have resulted in exclusive breastfeeding rates that are associated with maximum positive health outcomes. At this time, the proposed specific aims of the dissertation research are: 1) to identify significant factors that low income women consider to be barriers to sustaining exclusive breastfeeding, 2) to test the theoretical premises for social support and breastfeeding success, as indicated by breastfeeding duration and exclusivity, for low-income women, and 3) to develop and test an evidence-based cost-effective breastfeeding support intervention specifically for low-income women.