Background: Little is known about how preterm infants make the transition from breast-feeding and bottle feeding to exclusive breast-feeding in the weeks following hospital discharge. This study examined the breast-feeding patterns of preterm infants born at 30 to 35 weeks' gestation over a 4-week period following hospitalization. Method: Daily feeding diaries were completed by 53 mothers. These diaries were used to describe the proportion of breast milk feeds and feeds directly at breast. Results: Infants received a high proportion of breast milk feeds, with 60% receiving breast milk exclusively for the first week, and 56% receiving breast milk exclusively for the 4-week period. The proportion of feeds at breast increased steadily over the 4 weeks, with 50% primarily breast-feeding in week 4. Infants who received breast milk exclusively in week 1 were significantly more likely to be primarily fed directly at breast in week 4. Conclusions: Adequacy of the milk supply was a key factor in the successful transition from primarily bottle feeding at hospital discharge to primarily breast-feeding at home. The study provides some insight about this complex and poorly understood transition.