The objectives of this review are to describe the pathophysiology of refeeding syndrome, to synthesis the available evidence in critically ill children, and to provide practical recommendations for its prevention and management in paediatric intensive care units (PICUs). The refeeding syndrome appears in patients who have had a reintroduced and/or increase caloric intake after a period of restricted or no caloric intake. It is manifested by a decrease in one or many electrolytes (potassium, magnesium and/or phosphorous), a thiamine deficiency and/or sodium retention. Despite the lack of evidence, the patients most at risk for refeeding syndrome seem to be malnourished children and those with restricted nutritional intake for more than 7 days. On admission to PICU, nutritional status should be assessed, this should include anthropometric measurements (weight and height z-score, mid upper arm circumference and head circumference in young children) and a diet history. Indeed, nutrient intakes of the child prior to admission to PICU should be collected to identify whether the child’s intakes were decreased or inadequate in the weeks prior to hospitalization, including the number of meals and foods consumed per day. In children with low serum levels of potassium, magnesium and/or phosphorous, these imbalances should be corrected before nutrition support is commenced, along with supplement thiamine 100 mg per day. Current recommendations to avoid refeeding syndrome in critically ill children, are that energy intake should not exceed resting energy expenditure (REE) during the acute phase of critical illness and nutritional support must be increased progressively in a stepwise manner. Finally, the presence of a protocol to guide the timing and management of nutritional support in the PICU and the presence of a nutrition support team including a dedicated dietitian is recommended.