The continuous epidural anesthesia is an effective method for postoperative pain control and improvement of pulmonary function. A 39-year-old man was scheduled for postoperative intestinal obstruction. After adhesiolysis under the general anesthesia, epidural anesthesia was done for postoperative pain control. Because an accidental dural puncture was noticed, the adjacent interspace of epidural anesthesia was tried and catheter was inserted. Respiratory depression, hypotension, loss of consciousness and cardiac arrest were developed about 20 minutes after the first injection of 1% lidocain 10ml. Endotracheal intubation was performed and the respiration was controlled using 100% oxygen. Self respiration and alert mentality returned after 180 minutes. No CSF leakage, delayed onset time, severe hypotension, complete recovery may be the result of subdural anesthesia and postoperative hypoxia. But radiological examination was not performed.