Parenteral nutrition (PN) is the feeding modality of choice for patients with non-functional gastrointestinal (GI) tracts who are unable to maintain their nutrition and hydration enterally. Parenteral nutrition is a complex therapy involving the intravenous infusion of macro and micronutrients directly into the bloodstream for optimal absorption. The main components of parenteral formulas include dextrose, amino acids and lipids. Although PN is a lifesaving therapy for many patients, it is associated with serious short and long-term complications that can be life-threatening. Therefore, selection of the appropriate patient for parenteral therapy is crucial. This book discusses the policies, procedures, safe practices and potential of parenteral nutrition, as well as nutritional considerations for head and neck cancer patients; nutrition support teams and the role of registered dieticians; parenteral nutrition associated liver disease; and refeeding syndrome in children.