We conducted interviews prenatally and postpartum with 187 women, all of whom intended to breastfeed their newborns. However, 18% of these women either never initiated breastfeeding or stopped within one week. Among women who initiated breastfeeding, we identified four variables as significant predictors of failure to breastfeed for more than seven days: lower confidence in ability to breastfeed, less certainty in the decision to breastfeed, delayed first breastfeeding experience, and lack of rooming in with the baby. Results of this study suggest that women at high risk for not implementing their prenatal breastfeeding intention can be identified for additional support; interventions should focus on prenatal confidence building, early and continuing contact with the newborn, anticipatory guidance prior to discharge, and early pediatric follow-up.