Background: Intravenous regional anaesthesia (IVRA) is safe, technically simple but it has several disadvantages as limited duration, tourniquet pain and lack of post-operative analgesia. Objective: This study was carried out to evaluate the effect of adding ketamine versus dexamethasone to lidocaine on the characters of IVRA. Methods: This randomized double-blind controlled study was carried out on 75 patients scheduled for elective below elbow surgeries under IVRA. They were randomly allocated into three equal groups: Lidocaine group (L group) that received 3mg/kg lidocaine, Lidocaine/Ketamine group (L/K group) that received 3mg/kg lidocaine plus 0.1mg/kg ketamine and Lidocaine/Dexamethasone (L/D group) that received 3mg/kg lidocaine plus 8 mg dexamethasone. The primary outcomes were the characters of IVRA (onset, potency, tourniquet tolerance time and recovery time) and secondary outcomes were the hemodynamics (heart rate, mean arterial blood pressure and peripheral oxygen saturation) changes and the rate of the associated side effects. Results: Each of ketamine and dexamethasone produced a significant improvement of the characters of IVRA (i.e. enhanced onsets of both sensory and motor blocks, increased intra-operative analgesic potency, prolonged tourniquet tolerance time, and prolonged postoperative analgesia after release of tourniquet), non- significant hemodynamic changes beside absence of the associated side effects with superiority of ketamine over dexamethasone in enhancing the block onset, increasing block potency and in prolonging tourniquet tolerance time. Conclusion: Addition of each of ketamine and dexamethasone to lidocaine was safe and improved the characters of intravenous regional anesthesia, without associated side effects; however ketamine was superior to dexamethasone.