ANESTHESIA for shoulder operations can A be obtained by a single-injection brachial plexus block.1 The interscalene approach to the brachial and cervical plexuses is based on the concept of a continuous fascial sheath which extends from the cervical vertebrae to the axilla and contains elements of both the cervical and brachial plexuses. As the subclavian artery passes between the anterior and middle scalene muscles, it enters this sheath and continues distally within the sheath as the axillary artery. This report describes the onset of hoarseness and a Horner's syndrome (ptosis of the upper eyelid, miosis, and enophthalmos) secondary to stellate ganglion block after a cervicobrachial plexus block using a single interscalene injection.