Diazepam containing solvents such as propylene glycol & ethanol, causes pain on intravenous injection in most patients. The purpose of this study was to know the effect of lidocaine to reduce pain on iv injection of diazepam. Eighty patients were allocated four groups according to the lidocaine dosage & method of lidocaine administration; control group, diazepam 10 mg with no lidocaine, group 1, diazepam 10 mg with lidocaine 5 mg mixture; group 2, diazepam 10 mg with lidocaine 10 mg mixture, and group 3, diazepam 10 mg preceding lidocaine 10 mg under tourniquet. Results in this study showed that diazepam 10 mg with lidocaine 10 mg mixture(group 2) and diazepam with preceding lidocaine 10 mg under tourniquet(group 3) significantly reduced the incidence of pain without untoward effects of lidocaine on the cardiovascular system.