Background and Aim: Animal and human studies showed that intravenous infusion of lidocaine may have beneficial effects on reducing pain and faster recovery of bowel movements during postoperative period. The present study aimed to investigate the effect of lidocaine infusion on ileus after appendectomy. Methods: In this randomized double-blinded clinical trial, 40 patients undergoing appendectomy enrolled in the study. The regiment of anesthesia was similar in both groups. The lidocaine group received 1.5 mg/kg bolus dose injection of lidocaine immediately before induction of anesthesia and after endotracheal intubation infusion of lidocaine started with the rate of 3 mg/min (in patients weighing less than 70 kg, with 2 mg/ min). Infusion of lidocaine was continued during surgery and 60 minutes after it. The control group received normal saline using the same method and dosage as a placebo. After the surgery, up to 3 days, a blind observer recorded the patient’s systemic analgesic consumption and the time of first experienced passage of intestinal flatus. Results: Average of age, duration of anesthesia and gender distribution in both groups showed no significant difference (p>0.05). Average elapsed time from the end of operation to the first passage of flatus in the study group and the control group were 31.64±5.49 and 41.31±9.89 hrs, respectively (p<0.0001). The mean postoperative analgesic consumption (pentazocine) on the first day after operation in study and control group were 18±6.15 and 27.75±5.49 mg, respectively (p<0.0001). On the second day after surgery, 23 patients who had received analgesics, 5 individuals were in the study group and 18 individuals were in the control group (p=0.00007). Conclusions: The results of this study showed that lidocaine infusion during anesthesia and up to 1 hour after appendectomy reduces the duration of ileus and the need for systemic analgesic postoperatively.