Insulinomas are rare, mostly benign neuroendocrine tumours with an incidence of approximately four cases per million person per year. Only isolated case reports of insulinomas occurring in pregnancy have been documented. Clinical signs and symptoms of insulinoma appear to be attenuated and, in some cases, even masked by pregnancy. Therefore, in the present overview of insulinomas occurring during pregnancy, special attention is paid to potential factors contributing to the altered insulin response during pregnancy.