Background: This study aimed to determine the potential advantages of midazolam co-induction with general anesthesia (GA) over the use of propofol alone. Methods: We conducted a randomized, placebo-controlled, single-blinded clinical trial of 102 patients, aged 18 to 65, American Society of Anesthesiologists II and III, who underwent elective laparoscopic gallbladder surgery. Patients were randomly divided into 3 groups: the placebo group (C) received 1mL of 0.9% saline intravenously and the test groups received intravenous midazolam at doses of 0.03mg/kg (M1) or 0.06mg/kg (M2) before induction of GA. We assessed effects of midazolam co-induction on arterial pressure and heart rate (HR) in the early stage of GA prior to surgical incision and effects on perioperative and postoperative glycemia and cortisol levels. Systolic/mean/diastolic (SAP/MAP/DAP) arterial pressure and HR were measured 4 times (preoperative, on the third, sixth and ninth minute after atracurium administration). Cortisol was measured on 3 occasions (preoperatively, 60 minutes after surgical incision, and the following morning) and glucose on 4 occasions (preoperatively, 15 and 60 minutes after incision, and the following morning). We also assessed the incidence of postoperative anxiety, postoperative nausea and vomiting (PONV), and propofol requirement for induction. Results: SAP/MAP/DAP were significantly higher in M2 immediately after induction compared to the other study groups (P = .002/.004/.013). Midazolam co-induction led to a significant reduction in postoperative anxiety (P = .03), reduced cortisol concentration 60 minutes after surgical incision (P < .001) and propofol requirements (P < .001). Conclusion subsections: Midazolam co-induction prevented a marked decline in SAP/MAP/DAP immediately after induction of GA, led to reduced postoperative anxiety and cortisol response to surgery, and reduced propofol requirements for induction. Abbreviations: BIS = bispectral index monitoring, C = placebo/control group of patients, COR = cortisol, GA = general anesthesia, GLU = glucose, HR = heart rate, M1 = group of patients that received intravenous midazolam at dose of 0.03mg/ kg, M2 = group of patients that received intravenous midazolam at dose of 0.06mg/kg, MAC = minimum alveolar concentration, PONV = postoperative nausea and vomiting, SAP/MAP/DAP = systolic/mean/diastolic blood pressure, SAS = Zung’s Self-rating Anxiety Scale, TIVA = total intravenous anesthesia.