Accumulating evidences demonstrate that patients with diabetes have higher perioperative risk of complications and longer hospital stays than patients without diabetes. Intensive insulin therapy (IIT) may improve outcomes in hyperglycemic neurosurgical patients. However, currently there is no adequate data/evidence regarding optimal insulin delivery protocols and targeted blood glucose concentration during IIT. IIT continues to be explored as a therapeutic method to reduce morbidity associated with derangements in glucose metabolism. Hypoglycemia is a common side effect of IIT with the potential to result in significant morbidity, especially in patients undergoing neurosurgical surgery. Surgical stimulus is a potent cause which may affect patients stress response and influences the metabolic and endocrine system, which can lead to electrolyte imbalance and decrease of blood insulin level and subsequently result in impairment of immune response and increase of blood glucose level. The stress response can be prevented by sufficient Depth of anesthesia. So the Anesthesiologists play a very important role in manipulating the blood glucose of the diabetes patients during the neurosurgical operations. Narcotics affect systemic and cerebral metabolism, and studies indicate that most of anesthetics have restraining effects on brain oxygen and glucose consumption. In order to better regulate the blood glucose, the anesthesiologists should master the actions of every anesthetics. IIT is a double-edged sword; more investigations should be focused on optimising blood glucose level for euglycemia maintenance in the intraoperative management of diabetes neurosurgical patients.