The author describe a rare case of pancreatic beta-cell hyperplasia. The patient was referred to us because of serious hypoglycemic crises. During hospitalization, endogenous hyperinsulinism was confirmed by hematochemical and instrumental tests. AngioCT of the pancreas evidenced a small lesion of the corpus, suspected of insulinoma. The patient underwent a corpus caudalis pancreatectomy: a small nodule with histologic neuroendocrine traits was ablated. A few days after the operation, new symptomatic hypoglycemia appeared. The hormonal tests confirmed a recurrence of endogenous hyperinsulinism. The patient underwent a new operation for pancreaticoduodenectomy: histological examination confirmed a pancreatic beta-cells hyperplasia. This condition has to be taken into account in the differential diagnosis of post prandial hypoglycemia. Besides, the observation of an insulinoma doesn't exclude the presence of a diffused disorder of islet cells as in the case above described.