BACKGROUND The World Health Organization (WHO) developed the Baby-Friendly Hospital Initiative to improve hospital maternity care practices that support breastfeeding. In Hong Kong, although no hospitals have yet received the Baby-Friendly status, efforts have been made to improve breastfeeding support. The aim of this study was to examine the impact of Baby-Friendly hospital practices on breastfeeding duration. METHODS A sample of 1,242 breastfeeding mother-infant pairs was recruited from four public hospitals in Hong Kong and followed up prospectively for up to 12 months. The primary outcome variable was defined as breastfeeding for 8 weeks or less. Predictor variables included six Baby-Friendly practices: breastfeeding initiation within 1 hour of birth, exclusive breastfeeding while in hospital, rooming-in, breastfeeding on demand, no pacifiers or artificial nipples, and information on breastfeeding support groups provided on discharge. RESULTS Only 46.6 percent of women breastfed for more than 8 weeks, and only 4.8 percent of mothers experienced all six Baby-Friendly practices. After controlling for all other Baby-Friendly practices and possible confounding variables, exclusive breastfeeding while in hospital was protective against early breastfeeding cessation (OR: 0.61; 95% CI: 0.42-0.88). Compared with mothers who experienced all six Baby-Friendly practices, those who experienced one or fewer Baby-Friendly practices were almost three times more likely to discontinue breastfeeding (OR: 3.13; 95% CI: 1.41-6.95). CONCLUSIONS Greater exposure to Baby-Friendly practices would substantially increase new mothers' chances of breastfeeding beyond 8 weeks postpartum. To further improve maternity care practices in hospitals, institutional and administrative support are required to ensure all mothers receive adequate breastfeeding support in accordance with WHO guidelines.