To evaluate the efficiency and safety of intravenous (IV) remifentanil and propofol for gastroscopy in healthy adults.Randomized, double-blinded study.Endoscopy Center, West China Hospital, Sichuan University (Chengdu, People's Republic of China).199 adult ASA physical status I and II patients.Patients were randomly allocated to either the fentanyl group (n = 99) or the remifentanil group (n = 100). Patients received either fentanyl 0.5 μg/kg or remifentanil 0.5 μg/kg, followed by a bolus injection of one mg/kg of propofol. The subsequent doses of propofol were 0.5 mg/kg when the patient was conscious or body movement appeared.Noninvasive blood pressure, heart rate, arterial pulse oxygen saturation, and respiratory rate were recorded before gastroscopy and at two-minute intervals until the end of the gastroscopy procedure. Patients were asked to evaluate their level of cognition using the Digit-Symbol Substitution Test score before gastroscopy and at 10 minutes after discontinuation of the drug injection.Recovery time was significantly shorter in the remifentanil group than in the fentanyl group (P < 0.05). Postoperative Digit-Symbol Substitution Test scores were significantly higher in the remifentanil group than in the fentanyl group (P < 0.01). Total dosage of propofol given in the remifentanil group was significantly less than it was in the fentanyl group (P < 0.01). Frequency of apnea was significantly higher in the remifentanil group (P < 0.05). There were no significant differences in frequency of hypoxemia, bag ventilation, or body movement between the two groups (P > 0.05).Intravenous remifentanil and propofol were more efficient for gastroscopy than IV fentanyl and propofol.