This research examined the effect of peer support on breastfeeding duration and exclusivity (breastfeeding without supplements) in a population of low-income women during the first 3 months postpartum. Participants in the peer counselor group (n = 18) exhibited higher rates of exclusive breastfeeding across time than those without a counselor (n = 18), and more exclusive breastfeeding was associated with long duration overall. Mother's career plans had the greatest effect on duration of breastfeeding. Women who intended to return to work, attend school, or both breastfed 6 to 9 weeks less than participants who intended to stay home. Attendance at a breastfeeding class and knowing someone who had breastfed was significantly correlated with a longer duration of breastfeeding. Nutritionists from the Women, Infants and Children (WIC) Program were the primary source of breastfeeding information. Two main factors discouraged women from breastfeeding: returning to work, school, or both and the perception of a diminished milk supply. Greater emphasis should be placed on prenatal breastfeeding education for low-income women, and their mothers and grandmothers should be included. Peer support is one important component of social support in the area of breastfeeding that community health nurses (CHNs) can utilize. CHNs are in a unique position to assist working mothers, provide support, and develop educational programs to enhance breastfeeding success in this population.