Determinants of exclusive versus predominant breastfeeding in the maternity ward and the relationship with later feeding practices were investigated in 1656 mothers who breastfed exclusively or predominantly in the maternity ward. Mothers were interviewed through 12 months postdelivery about feeding practices. Information about the World Heath Organization's (WHO's) 10 steps was collected. At hospital stay, breastfeeding was predominant in 43% of infants. Cesarean section (odds ratio [OR] = 1.75), mother's overweight (OR = 1.74), and non-compliance with the WHO's steps 6 (OR = 1.58), 7 (OR = 1.43), and 8 (OR = 1.76) were determinants of predominant, as opposed to exclusive, breastfeeding. Mothers exclusively, rather than predominantly, breastfeeding in the hospital showed a longer duration of full breastfeeding (mean = 3.6 vs 3.1 months), later introduction of formula (3.8 vs 3.3 months), and lower rate of introduction of formula within 1 month (23% vs 30%). Hospitals need to be compliant with the WHO's steps, and Baby-Friendly Hospital Initiatives should be promoted.