AIM: To analyze the hemodynamic and respiratory effects of propofol on patients undergoing gastroscopy and colonoscopy.METHODS: In this prospective study, conducted over a period of three years, 1,104 patients referred for a same day GI endoscopy procedure were analyzed. All patients were given a propofol bolus (0.5-1.5 mg/kg). Arterial blood pressure (BP) was monitored at 3 min intervals and heart rate and oxygen saturation (SpO2) were recorded continuously by pulse oximetry. Analyzed data acquisition was carried out before, during, and after the procedure.RESULTS: A statistically significant reduction in mean arterial pressure was demonstrated (P＜0.001) when compared to pre-intervention values, but severe hypotension, defined as a systolic blood pressure below 60 mmHg, was noted in only 5 patients (0.5%). Oxygen saturation decreased from 96.5% to 94.4 % (P＜0.001).A critical decrease in oxygen saturation (＜90%) was documented in 27 patients (2.4%).CONCLUSION: Our results showed that propofol provided good sedation with excellent pain control, a short recovery time and no significant hemodynamic side effects if carefully titrated. All the patients (and especially ASA Ⅲ group) require monitoring and care of an anesthesiologist.