OBJECTIVE To describe mothers' exclusive breastfeeding intentions and whether Baby-Friendly hospital practices are associated with achieving these intentions. METHODS In the 2005-2007 Infant Feeding Practices Study II, women completed a prenatal questionnaire and approximately monthly questionnaires through 12 months. Mothers met their prenatal exclusive breastfeeding intention if their duration after the hospital stay (excluding hospital supplementation) equaled or exceeded their intention. Primary predictor variables included 6 Baby-Friendly hospital practices: breastfeeding within 1 hour of birth, giving only breast milk, rooming in, breastfeeding on demand, no pacifiers, and information on breastfeeding support. RESULTS Among women who prenatally intended to exclusively breastfeed (n = 1457), more than 85% intended to do so for 3 months or more; however, only 32.4% of mothers achieved their intended exclusive breastfeeding duration. Mothers who were married and multiparous were more likely to achieve their exclusive breastfeeding intention, whereas mothers who were obese, smoked, or had longer intended exclusive breastfeeding duration were less likely to meet their intention. Beginning breastfeeding within 1 hour of birth and not being given supplemental feedings or pacifiers were associated with achieving exclusive breastfeeding intention. After adjustment for all other hospital practices, only not receiving supplemental feedings remained significant (adjusted odds ratio = 2.3, 95% confidence interval = 1.8, 3.1). CONCLUSIONS Two-thirds of mothers who intend to exclusively breastfeed are not meeting their intended duration. Increased Baby-Friendly hospital practices, particularly giving only breast milk in the hospital, may help more mothers achieve their exclusive breastfeeding intentions.