ABSTRACT This study aimed to evaluate the impact of glucose administration in form of 5% dextrose in 0.9% saline (DNS) alternately with lactated ringer's solution (RL) starting prior to induction of anesthesia on blood glucose level (BGL) in patients assigned to have neurosurgical procedures extending for more than 4 hours. The study included 46 (27 males and 19 females) adult non-diabetic elective neurosurgical patients in ASA grade I and II with mean age of40±6.6 years. Patients were maintained on overnight fasting for 8 hours with no preoperative intravenous fluids administration and were randomly allocated into 2 equal groups: DNS/RL group received 500 ml of DNS and RL solutions alternately and RL/NS group received 500 ml of RL and 0.9% normal saline (NS) alternately. The study was terminated at the end of administration of two liters of fluid or if BGL decreased to