Insulinoma is a rare functional pancreatic neuroendocrine tumour that is usually sporadic and solitary. It can have a varied presentation. Neuroglycopenic manifestations of hypoglycemia due to insuline hypersecretion can mimic neurological or psychiatric disorders, thus often a diagnosis and treatment delay. Insulinoma is a potentially curable condition, but it can be fatal if left unrecognized. We report a case of A 45-year-old woman who had a 9-year delay before diagnosing insulinoma after being initially assessed with anxiety–depressive disorder. The case report below provides a detailed review of the diagnosis, tumour localization, and the successful surgical intervention implemented for the patient.