Congenital heart defects are known causes of malnutrition. Optimal nutritional management is paramount in improving short and long-term prognosis for neonates and infants with congenital heart malformations, as current strategies target preoperative and postoperative feeding requirements. Standardized enteral and/or parenteral feeding protocols, depending on the systemic implications of the cardiac defect, include the following common practices: diagnosing and managing feeding intolerance, choosing the right formula, and implementing a monitoring protocol. The latest guidelines from the American Society for Parenteral and Enteral Nutrition and the European Society of Paediatric and Neonatal Intensive Care, as well as a significant number of recent scientific studies, offer precious indications for establishing the best feeding parameters for neonates and infants with heart defects.