Total spinal anesthesia following intrathoracic intercostal nerve blocks with bupivacaine performed for postoperative pain relief during thoracotomy is described. Possible mechanisms for this complication include: (1) inadvertent placement of the needle through an intervertebral foramen, (2) puncture of a long dural cuff, and (3) intraneural injection with central spread. Recognition of this potential complication is important, and facilities for proper support must be available.