UNLABELLED: Few studies have concerned the rare functioning endocrine pancreatic tumors associated with multiple endocrine neoplasia type 1 (MEN 1). When sporadic, these tumors have a poor prognosis. AIM: To analyze the frequency, characteristics and prognosis of MEN 1-associated glucagonomas, VIPomas and somatostatinomas recorded in the GTE (Groupe des Tumeurs Endocrines) registry. METHODS: Records of the patients whose GTE registry codes included glucagonoma, VIPoma or somatostatinoma were reviewed. The diagnosis was confirmed when there were clinical signs of a functioning tumor and/or when blood levels of the peptide were higher than twice the upper limit of normal. RESULTS: Among 580 patients with MEN 1, duodeno-pancreatic involvement was present in 307 (52.9%). Five (1.6%) had a glucagonoma, 3 (0.98%) a VIPoma and 2 (0.65%) a somatostatinoma. A clinical syndrome was present in 1 patient with glucagonoma, in the 3 with VIPomas and in 1 with somatostatinoma. Tumor size was greater than 3 cm more often for these rare tumours (67%) than in patients with other type of duodeno-pancreatic involvement (28%) (P=0.02) and visceral metastases were more frequent (40% vs 15%; P=0.056). Ten-year survival of patients with glucagonomas, VIPomas or somatostatinomas (53.8%; CI95%: 15.5-92.1) was poorer than that of patients with insulinomas (91.4%; CI95%: 83.399.5; P=0.01) or gastrinomas (81.7%; CI95%: 74.9-88.5; P=0.20) and close to that of patients with non-functioning tumors (62.2%, CI95%: 41.0-83.9; NS). CONCLUSION: Glucagonomas, VIPomas and somatostatinomas, especially the functioning type, are very rare in patients with MEN 1. Prognosis is poor, probably because of large tumor size and high rate of metastasis. Survival is similar to that in patients with non-functioning tumors.