The importance of optimal nutrition has been well demonstrated in Cystic Fibrosis patients; it affects their mortality, diminishes morbidity and could decrease the deterioration of pulmonary function. However, success of nutritional treatment depends mostly of its early onset. Assistance by enteral route as well as gastrostomy in early stages becomes important since early detection of nutritional deficits and active support result in better response to treatment and slower deterioration of pulmonary function. With an increased survival, new nutritional challenges appear, like deficits of specific EFA, micronutrients, minerals, and possible antioxidant and anti-inflammatory effects of various nutrients. The object of this article is to update nutritional treatment of children and adolescent CF patients.