Although the small intestine represents 75% of the length and over 90% of the mucosal surface of the alimentary tract, it is the site of only about 2% of malignant gastrointestinal tumours. Adenocarcinoma is the most common histological subtype, accounting for about 40% of all malignant small intestinal tumours. The infrequent occurrence when compared with malignancies of the stomach and colon is accompanied by non-specific clinical symptoms. The consequences are a significant delay in diagnosis and the finding of advanced, incurable disease at operation. Wide surgical resection of early lesions is the only potentially curative treatment, but it is possible only in a minority of patients. The rare nature of adenocarcinomas of the small intestine has led to a paucity of information about the benefits of adjuvant chemotherapy but there are reports of overall better survival for those patients that receive combination treatment. Most chemotherapy regimens consist of 5-fluorouracil (5-FU), alone or in combination with a variety of other agents like doxorubicin, cisplatin, mitomycin C, cyclophosphamide and oxaliplatin.