Abstract Introduction To our knowledge, successful breastfeeding in the population with single ventricle congenital heart disease has not been reported in the literature, particularly during the interstage period. Method A retrospective case study including inpatient nutrition and a complete history of daily logs with the home surveillance monitoring program was performed. Results Successful full breastfeeding (exceeding prescribed weight growth goals) after Stage I surgery was achieved during the interstage period. The infant was discharged at 3.41 kg, not consistently breastfeeding, and progressed to 7.05 kg at 5 months of age, fully breastfeeding. Conclusion Supporting breastfeeding for infants who have undergone repairs for single ventricle anatomy can be challenging but can be accomplished. It requires a concerted team effort, clear communication, and collaboration among caregivers, the mother, and her supporters.