We report a series of 30 patients with pancreatic insulinoma treated from 1967 to 1990. Twenty-nine patients underwent surgery. In 24 patients, the lesion was a benign adenoma. The pancreatic lesion was localized preoperatively in 59% of cases (94% since 1980), and all lesions that were identifiable histologically were palpable intraoperatively. Endoscopic pancreatic ultrasonography, performed twice, appeared to be a very promising method of investigation. In the 24 patients with adenoma, 14 enucleations and 10 pancreatic resections were performed, with the enucleation rate increasing over time. One patient died during the postoperative period. Pancreatic fistulas (43%) were the most common cause of morbidity and were more common after enucleation (57% versus 29% after pancreatectomy). The mean follow-up period was 7 years. Excluding the patients with adenocarcinomas, the recovery rate was 92% (23 of 25 among whom 2 patients had transitory recurrent hypoglycemia), 2 patients who underwent corporeo-caudal pancreatectomy being diabetic (8%).