Background and Clinical Significance: Endogenous hyperinsulinemic hypoglycemia (HHE) is a rare cause of hypoglycemia, primarily associated with insulinomas, the most common functional pancreatic neuroendocrine tumors. This clinical case explores the diagnostic and therapeutic challenges in patients with recurrent hypoglycemia and no history of diabetes, emphasizing the importance of a multidisciplinary approach to optimize outcomes. Case Presentation: We present a 45-year-old woman presenting with severe hypoglycemic episodes and persistent neuropsychiatric symptoms for over a year. Prolonged fasting tests, insulin and C-peptide level measurements, and specialized imaging studies (endoscopic ultrasound and pancreatic protocol computed tomography) were conducted. Surgical resection of the identified lesion was subsequently performed. Diagnostic studies confirmed a well-differentiated 2.5 cm insulinoma, treated with partial pancreatoduodenectomy. The patient developed postoperative complications that required interdisciplinary management, ultimately achieving clinical stabilization and sustained normoglycemia. Conclusions: This case underscores the importance of considering insulinoma in the differential diagnosis of recurrent hypoglycemia in non-diabetic patients, using Whipple’s triad as a key diagnostic criterion. It also highlights the role played by comprehensive strategies combining functional testing (e.g., prolonged fasting) and advanced imaging to ensure timely treatment and reduce the risk of chronic complications.