Propofol is a rapidly acting intravenous anesthetic agent used for the induction of anesthesia, with a low incidence of side effects. But pain on injection of propofol has limited its use. The additional effect of lidocaine on painful injection of propofol was studied, during induction of general anesthesia in 75 patients in a prospective, randomized method. They were allocated randomly to three groups to receive propofol 2.0 mg/kg(group A), propofol 2.0 mg/kg with lidocaine 0.2 mg/kg(group B), propofol 2.0 mg/kg with lidocaine 0.3 mg/kg(group C). Pain score was assessed on a simple scale graded from 0 (no pain) to 3 (severe pain). Mean arterial blood pressure and heart rate were monitored at 1, 3, 5, 7 minutes after endotracheal intubation. In group B and C, significantly smaller pain score was observed. On the other hand, changes of mean arterial blood pressure and heart rate after endotracheal intubation was not significant. It is concluded that the addition of small amount of lidocaine can significantly reduce the severity of pain on injection of propofol.