It is clear that the nutritional state of patients with inflammatory bowel disease is often impaired and that the provision of nutritional support results in an improvement in nutritional state of these patients. Improvement in nutritional status can be achieved as effectively with enteral as with parenteral nutrition. The nutritional support appears to have no primary therapeutic effect in patients with ulcerative colitis. With regard to nutritional support in Crohn's disease, parenteral nutrition should be restricted to use as supportive rather than primary therapy. Available information now seems to suggest that most of the benefits of parenteral nutrition in Crohn's disease are related to improvement in nutritional state rather than as primary therapy, and its use should be restricted to treatments of specific complications of Crohn's disease, such as intestinal obstruction, related to stricture formation or short bowel syndrome following repeated resection. The present available evidence indicates that defined elemental diets may have a primary therapeutic role in the management of first acute attacks of Crohn's disease when there is a need to improve the nutritional status of patients with inflammatory bowel disease as an adjunct to primary drug therapy. Enteral nutrition is as efficacious as parenteral nutrition; moreover, it is safer to administer and more cost-effective.