In recent years, we have witnessed an increasing number of outpatient upper limb surgeries performed under regional anesthesia. Clinicians are encouraged to consider a number of factors that can improve block success and minimize complications. These factors include knowledge of the applied brachial plexus anatomy, thorough understanding of sensory and motor innervation relevant to the surgical site, appropriate choice of block technique and local anesthetic agent, the use of adjuncts that can facilitate block onset, and recovery and application of rescue techniques for incomplete block in a timely manner. When properly conducted, upper extremity blocks in outpatients do not delay operating room time but facilitate patient recovery and hospital discharge time. Copyright © 2000 by W.B. Saunders Company