Crohn's disease is a chronic inflammatory disease of the bowel for which there is no curative treatment. The purpose of treatment is to reduce mortality to the absolute minimum and to give the patients a normal quality of life. Acute episodes of low severity are treated with sulfasalazine and its most recent derivatives such as 5-aminosalicylate. More severe episodes require oral corticosteroid therapy which, when prescribed in adequate doses, results in clinical remission in over 90% of the cases. To this must be added parenteral nutrition in patients with very severe symptoms or when a major nutritional deficit is present. During remissions, a maintenance treatment with 5-aminosalicylate or azathioprine is justified when the acute episodes are frequent and/or severe. These continuous chronic forms require prolonged low-dose corticosteroid therapy or azathioprine. Artificial nutrition is the best way of treating corticosteroid-resistant episodes. In children, corticosteroids must be avoided as much as possible, and low-flow rate enteral nutrition is often used as primary treatment of salicylate-resistant episodes. The surgical treatment of Crohn's disease consists of resection of the lesions with anastomosis or ileostomy in case of total proctocolectomy. Following resection-anastomosis, the cumulative relapse rate is about 50% ten years after surgery; it is lower after colostomy and proctocolectomy. Surgery is indicated in case of complications (abscesses, stenosis, fistulae, perforation) and when the disease does not respond to a well-conducted medical treatment. Specialized teams including physicians, surgeons, proctologists and specialists in nutrition are essential to a correct treatment of Crohn's disease.