This study aimed to compare the effects of low and same dose of dexmedetomidine when added to lidocaine for intravenous regional anesthesia (IVRA) and when administered for premedication before IVRA. In this double blind study, 45 patients with ASA physical status I-II were scheduled to undergo carpal tunnel release as an outpatient procedure and were randomly divided into three groups. IVRA was performed with 40 mL of 0.5% lidocaine in the operating room. A single dose of dexmedetomidine 0.5 μg/kg and placebo (saline) solution in a total volume of 20 mL were administered intravenously to group P (n=15) and group S (n=15), respectively, before IVRA. 0.5 μg/kg of dexmedetomidine was added to lidocaine in group A (n=15) during IVRA. The onset and recovery time of sensory and motor block, intraoperative-postoperative visual analog scale (VAS) and Ramsay sedation scores (RSS), analgesic requirement, hemodynamic variables, and side effects were noted. Significantly shortened sensory block onset and recovery time in group P and A, shortened motor block onset time in group P, and decreased intra-postoperative VAS scores and analgesic requirement in groups P and A were found. Intraoperative RSS in group P and postoperative RSS in groups P and A were higher than in group S. Intraoperative and postoperative heart rate and postoperative mean arterial blood pressure (MAP) of group P was significantly lower than groups A and group S, respectively. Both addition of dexmedetomidine to lidocaine and premedication with dexmedetomidine for IVRA similarly improve quality of anesthesia and perioperative analgesia without important side effects.