P Pu ur rp po os se e: : The aim of this study was to evaluate the effectiveness of lidocaine, propofol and ephedrine in suppressing fentanyl-induced cough.M Me et th ho od ds s: : One hundred and eighteen patients were randomly assigned into four groups and the following medications were given intravenously: patients in Group I (n = 31) received normal saline 2 mL, Group II (n = 29) received lidocaine 2 mg·kg and Group IV (n = 28) received ephedrine 5 mg. At one minute after the study medication, fentanyl 2.5 µg·kg -1 was given intravenously within two seconds. The occurrence of cough and vital sign profiles were recorded within two minutes after fentanyl bolus by an anesthesiologist blinded to study design.R Re es su ul lt ts s: : Sixty-five percent of patients in the placebo group had cough, whereas the frequency was significantly decreased in Groups II (14%) and IV (21%). Although a numerically lower frequency of cough was noted in Group III (37%), it was not statistically different from that of the placebo group. SpO 2 decreased significantly in patients of Group III compared to placebo; one patient experienced hypoxemia necessitating mask ventilation. Patients in Group III showed a decrease in heart rate and systolic blood pressure (2 beats·min