Major burns are a devastating traumatic condition that is completely dependent on nutrition therapy for survival and recovery. On admission, the severity and outcome depend on the total body surface area (BSA) burned, the presence of inhalation injury, and the age of the patient. Some specificities distinguish them from other trauma patients: the skin destruction, a massive oxidative stress, immune depression (humoral and cellular) starts within hours after injury and the long-lasting alterations of endocrine and metabolic changes. In major burns, i.e., burns >20% BSA, the energy requirements vary over time and should ideally be measured by indirect calorimetry and, in its absence, be guided by the Toronto equation, but intakes should never be under 20 kcal/kg/day. Protein requirements are high with 1.3–1.5 g/kg/day. Carbohydrates are essential and should represent about 55% of energy intake, as glucose is the principal energy source for rapidly replicating cells such as the leucocytes and healing wounds. Blood glucose should be kept under 10 mmol/l. Micronutrient needs are elevated, particularly those of the B family, ascorbic acid and vitamin D, and the trace elements copper, selenium, and zinc: the latter need special attention during the first weeks after injury as they are lost with the exudates creating an acute depletion. Nutrition therapy requires close monitoring.