Growth in children with congenital heart disease (CHD) is often compromised. For several decades, investigators have tried to identify the factors affecting growth in children with CHD. Cardiac malformations are undoubtedly responsible for malnutrition, which may range from mild undernutrition to severe failure to thrive (FTT). Malnutrition may then significantly undermine the outcome of corrective surgical operations and postoperative recovery. Mechanisms linking CHD to malnutrition may be related either to decreased energy intake and/or to increased energy requirements. Decreased energy intake can involve deficiencies of specific nutrients, or insufficient total caloric intake. Increased respiratory rate accompanying congestive heart failure may be responsible for increased energy requirements. Different types of cardiac malformations and consequent interventions may have different effects on growth and require diverse strategies. Most treatment strategies aim to facilitate “catch-up” growth, providing extra calories and protein that exceed the Recommended Dietary Allowance for age. However, there is no generally accepted set of guidelines that define appropriate caloric intake for catch-up growth. We attempt to identify the most important causes of malnutrition and highlight the most effective nutrition strategies for children with CHD.