Malnutrition is common and undiagnosed in the majority of affected hospital patients; it is associated with impaired organ function, morbidity, and increased length of hospital stay. Artificial nutritional support in malnourished patients leads to improvement in nutritional status and clinical outcome. Nutritional support is required in malnourished patients, patients who are unable to take normal diet and patients with intestinal failure. Gastroenterologists are required to supervise patients with intestinal failure, to insert endoscopic feeding devices, and increasingly to participate in, or lead, nutritional support teams. Major developments in nutrient delivery have included percutaneous endoscopic feeding devices, the recognition that enteral feeding is possible in patients with gastric stasis, and that nutrient needs can be met by peripheral parenteral nutrition. There is much interest in the use of new substrates, or substrates delivered in pharmacological doses such as glutamine and arginine, to manipulate the response to disease. Many hospitals lack an organized approach to artificial nutritional support. Patients continue to suffer from a lack of treatment or the consequences of inappropriate or inadequate treatment. This article reviews the current status of artificial nutritional support and provides guidelines for patient management.