In thisl study,80 patients,aged 35-60 , class I, II America Society of Anesthesiology, candidate for elective laparoscopic cholecystectomy, randomly divided into 2 equal 40 patients. Patients with a history of seizures and psychiatric disorders are excluded. The patients receive Gabapentin 600 mg in intervention group and capsule without Gabapentin ,empty capsule, orally as a placebo in control group 1.5 hours before surgery. Anesthetic premedication included midazolam( 0.01-0.03 mg/kg), fentanyl (3µg/kg), morphine( 0.1mg/kg), dexamethasone( 8mg), metoclopramide(10 mg) and lidocaine (1mg/kg) l. Anesthesia induced with Sodium thiopental (5mg/kg) and atracurium (0.5mg/kg). Anesthesia is maintained with Isoflurane0.6-1.2% and N2O 50% plus O2 50%.All patients receive intravenous meperidine( 25 mg) after gallbladder removal. The patients are reversed with 2.5mg Neostigmine and 1mg Atropine. The Pain score evaluate with Visual Analog Scale (0-10) every 2 hour for 12 hours then every 6 hour for next 12 hours. If the pain scores greater than 4, Intravenous Morphine( 3 mg ) is administrated. All patients evaluate for nausea and vomiting, vertigo and drowsiness for 24 hours. Finally,we compare Morphine consumption and patient’s pain scores of two groups.