Nutritional support in pediatric patients receiving extracorporeal membrane oxygenation (ECMO) therapy is controversial. Although ECMO is increasingly used in pediatric intensive care units, there is no consensus on the optimal approach for nutrient prescription in this patient population. It is imperative to understand that this population experiences severe metabolic stress, which increases their nutritional demands, consequently leading to higher morbidity and mortality in pediatric patients on ECMO. This narrative review aims to summarize the current medical evidence on aspects of nutritional support in pediatric patients with ECMO, including nutritional adequacy, nutrient administration routes, and enteral and parenteral nutrition, as well as the proposal of an algorithm for initiating medical-nutritional therapy in this population.