Purpose: This study was performed to evaluate the effect of low-dose lidocaine on fentanyl-induced cough and hemodynamic changes under general anesthesia. This research was a randomized trial design and performed using a double-blind method. Methods: Data collection was performed from October 22, 2008, to May 4, 2009. One hundred and thirty two patients were randomly assigned to control group (Con G) and experimental group (Exp G) using a table of random numbers. Exp G (n=66) were administered 0.5 mg/kg lidocaine and Con G (n=66)) were administered saline. The occurrence of cough and vital sign were recorded within one minute after fentanyl bolus by an anesthesiologist. Collected data were analyzed using Repeated measures ANOVA using SPSS for Windows (Version 17.0). Results: The incidence of cough in Exp G was 13.6%, while Con G was 53%. The incidence cough in Exp G was significantly lower compared to Con G (p<.001). Lidocaine seemed not to suppress mean arterial pressure (p=.145), heart rate (p=.508), and oxygen saturation (p=.161). Conclusion: Intravenous administration of 0.5 mg/kg lidocaine seems to suppress fentanyl-induced cough without affecting mean blood pressure, heart rate and oxygen saturation. Therefore, we recommend intravenous 0.5 mg/kg lidocaine administration to suppress fentanyl-induced cough under general anesthesia.