There are multiple sites at which the brachial plexus block can be induced in selecting regional anesthesia for upper extremity surgical patients. The most frequently used blocks are axillary, infraclavicular, supraclavicular, and interscalene. One must understand brachial plexus anatomy to use these blocks effectively, as well as the practical clinical differences between the blocks. Axillary brachial plexus block is most effective for surgical procedures distal to the elbow. This block is induced at a distance from both the centroneuraxis and the lung; thus, complications in those areas are avoided. Infraclavicular block is often the most effective method of maintaining a continuous block of the brachial plexus, since the catheter is easily secured to the anterior chest. Supraclavicular block provides anesthesia of the entire upper extremity in the most consistent, time-efficient manner of any brachial plexus technique; however, the block needle is necessarily positioned near the lung during injection. Interscalene block is especially effective for surgical procedures involving the shoulder or upper arm because the roots of the brachial plexus are most easily blocked with this technique. The final needle tip position with this block is potentially near the centroneuraxis and arteries perfusing the brain, thus careful aspiration of the needle and incremental injection are important. In summary, when an understanding of branchial plexus anatomy is combined with proper block technique and a patient- and procedure-specific balancing of risk-benefit, our patients and colleagues will be coadvocates of our branchial plexus regional blocks.