The place of the long-acting somatostatin analogue octreotide in the management of symptoms in patients with functional gastroenteropancreatic (GEP) tumors and of growth in patients with metastatic disease is reviewed in this report. Numerous studies indicate that octreotide is, currently, the therapeutic principle of first choice in the symptomatic treatment of patients with carcinoid syndrome, Verner-Morrison syndrome and glucagonoma syndrome but not of insulinoma and gastrinoma patients. A beneficial effect on tumor growth has been demonstrated in 40% of patients with metastatic GEP tumors with stabilization of the disease as the most favorable response. However, further studies have to identify subgroups of patients in whom octreotide alone or in combination with alpha-interferon inhibits tumor growth.