This study was performed to compare the transarterial (T) and paraarterial (P) approaches for brachial plexus block, in terms of success rate, onset time and duration of analgesia and complications. Hundred patients scheduled for elbow, arm or hand surgery at Tabriz Shohada hospital from October 2005 to December 2006, randomly allocated into two groups (n = 50 per group), based on the approach chosen to block the brachial plexus. For local anesthesia each patient received 22.5 mL of 2% lidocaine with 17.5 mL distilled water (in total volume of 40 mL and total dose of 450 mg) and 1/200000 epinephrine with a standard 23 gauge needle. All patients were sedated with 1 μg kg-1 of fentanyl and 0.02-0.05 mg kg-1 of midazolam. There was no statistical difference between the groups in duration of analgesia but the onset of anesthesia was significantly quicker in paraarterial technique (3.5 vs. 13.4 min, p<0.001). Success rate was 86% in group T and 98% in group P (p = 0.03). Two percent of patients in group P and 6% in group T had total failure of the block and 8% of the group T required supplementary drug. Paraarterial method for axillary block is preferable due to quicker onset of blockade and higher success rate.