Background: The present study has evaluated the effect of intrathecal Sufentanil and Meperidine on patients’ shivering after caesarean section. Methods: The present study was a double-blind randomized clinical trial that was conducted on 120 patients. Spinal anesthesia was administered using 2 cc (10 mg) of bupivacaine along with 2.5 µg (0.5 cc) of Sufentanil for the first group, 25 mg (0.5 cc) of Meperidine for the second group and 0.5 cc normal saline for the control group. The severity of patients’ shivering was recorded during the surgery and in the recovery room. Heart rate, respiratory rate, systolic and diastolic blood pressures, oxygen saturation, and core and skin temperatures were measured before anesthesia, 5th minute, 10th minute and then every 15 minutes until the end of the surgery and then every 15 minutes into the recovery until discharge from recovery. The Apgar score of the neonates were also recorded at the 1st and 5th minutes after birth. Results: The mean score of shivering was significantly lower in the Meperidine group (0.1 ± 0.07) than the Sufentanil group (1.2 ± 0.3) and the control group (4.1 ± 0.5) (p 0.05). Conclusion: Using intrathecal Meperidine and Sufentanil, besides decreasing the incidence of shivering (with more effectiveness from Meperidine), would also increase the block density and quality of relaxation in the patients. It would also lead to improved hemodynamic stability without affecting the sensory block level and infant’s Apgar score.