Post-partum hypoglycemia in non-diabetic women is a rare condition. We report the exceptional case of a 38-year-old obese woman who experienced recurrent neuroglycopenia 3 weeks after delivery. Corresponding to severe hypoglycemia with blood glucose levels of <30 mg/dL, there was no suppression of insulin or C-peptide. Through endoscopic ultrasound we detected a hypoechoic lesion of 8 × 9 mm localized in the head of the pancreas. Thus, the diagnosis of insulinoma was most probable. Complete surgical enucleation of the insulinoma resulted in immediate and permanent resolution of hypoglycemia. The postoperative course was complicated by recurrent episodes of pancreatitis requiring endoscopic ultrasound-guided punctures of pseudocysts and temporary stenting of the pancreatic duct. In conclusion, insulinoma is a very rare, nonetheless important, differential diagnosis of post-partum hypoglycemia.