Brachial plexus block may cause many complications such as pneumothorax, inadvertent subarachnoid or epidural blockade, permanent neurologic damage to the motor outflow of the brachial plexus, hoarseness, Homer's syndrome, carotid bruit, convulsions, phrenic nerve palsy, etc. Since Winnie (1970) introduced interscalene approach for brachial plexus block, this has been one of the most popular methods in recent years because of infrequent complications and the technique is still considered safe. We experienced a rare, unusual complication after interscalene approach in a thirty eight year old woman. She was scheduled for left index finger amputation because of crushing injury. A 20 ml of 2% lidocaine and 20 ml of 0.5% bupivacaine was injected through interscalene groove after paresthesia was elicited on the patient's left thumb. Fifteen minutes after injection, she complained of respiratory difficulty and became apneic after five minutes later, and finally she did not respond to stimulation. Endotracheal intubation was proceded for respiratory support. Although neuromuscular blocking drug was not injected, vocal cord was paralysied on laryngoscopy. Pupillary light reflex and eye lash reflex were abscent. Blood pressure and heart rate decreased slightly. Ninety minutes after conservative treatment, self respiration was restored and pupillary light reflex and consciousness were recovered. She was discharged from recovery room to general ward after 4 hours without any events. We suspected that local anesthetics might be injected through epidural space or subarachnoid space in this patient.