Background: Spinal anesthesia has been associated with intraoperative nausea and vomiting (IONV), especially during cesarean section, which is attributed to several mechanisms.Objectives: In the present study, therapeutic and preventive properties of sub hypnotic dose midazolam and propofol and their effects on the occurrence and severity of intraoperative nausea and vomiting during elective cesarean section under spinal anesthesia were evaluated.Patients and Methods: In a randomized, double-blind, and placebo-controlled clinical trial, 90 parturients, ASA class I and II, aged 20-30 years, who undergone spinal anesthesia for cesarean section were randomly allocated to one of three groups receiving midazolam (1 mg bolus and 0.1 mg/kg/hr, n=30), propofol (20 mg bolus and 0.1 mg/kg/hr, n=30), and placebo (saline, n=30) intravenously (IV) immediately after umbilical cord clamping. Bupivacaine hydrochloride (10 mg) was used for induction of the anesthesia. Patients’ hemodynamics was monitored at 3-minute intervals. Furthermore, intraoperative and post-delivery emetic episodes, severity of emesis, scores of sedation and ephedrine consumption were recorded.Results: The incidence of nausea, retching, and vomiting was significantly higher in the control group compared to propofol and midazolam groups. Overall, PONV (postoperative nausea and vomiting) in midazolam group was as low as propofol group without any significant hemodynamic changes as seen in placebo group or even with propofol group.Conclusions: Subhypnotic doses of midazolam or propofol are effective in the prevention of nausea and vomiting during and after cesarean section with spinal anesthesia and does not significantly influence hemodynamic of the patients.