Background:A suitable sedative status during gastro-enteric endoscopies results in better physicians’ approach and more stable view of internal organs. Therefore, we evaluated the effect of ketamine for sedation in endoscopic procedures of adult patients.Materials and Methods:Patients who were candidates for gastro-enteric endoscopy during the years 2014-2015 were included into the study and divided into two groups of case (administered 5 mg/kg of oral ketamine half an hour before initiation of the procedure) and control (administered placebo in a same pattern). After endoscopy, patients and physicians’ satisfaction of sedation was assessed. SPSS-22 was used for data analysis.Results:Eighty-six patients participated into the study of which divided into each groups. The pain and discomfort scores were 2.4 ± 1.8 and 5.81 ± 1.48 in case and control groups, respectively, (P < 0.001). Mann-Whitney test revealed statistical difference among groups about physician's satisfaction of sedation during endoscopy (P < 0.001). Patients who received ketamine had better sedative status (P < 0.001). None of the patients in the case group was completely awake but all of the patients in the control group were awake. The number of retching during endoscopy showed that individuals in the control group had more frequent retching episodes (P = 0.04).Conclusion:Low-dose oral administration of ketamine could make a satisfied sedation for gastro-enteric endoscopy.