Epidural anesthesia is widely used in patients who undergo thoracic, abdominal or lower extremity surgeries and generally considered useful for perioperative analgesic management. Epidural catheterization is often associated with some complications including misplacement of the catheter. Epidural catheters are known to be misplaced or migrate into subarachnoidal space, subdural space, vessels and thoracic cavities ; however, frequency, predominant sites of misplacement, and the timing of detection are not fully understood regarding the misplacement of the catheters. In this retrospective study, our incident reporting system dealt with a period of 8 years (from 1999 to 2007) at our university hospital. Out of 8 patients who had misplacement of the catheter, 6 patients were male and 2 patients were female. Epidural catheters were misplaced to subarachnoid space in 6 cases and thoracic cavity in 2 cases. The misplacement of the catheters was found before the induction of general anesthesia in 2 patients, after induction of general anesthesia in 1 patient, during surgical procedure in 3 patients, and postoperatively in 2 patients. Since misplacement of epidural catheters can occur at any moment during perioperative period, continuous monitoring and observation of patients seem to be very important to prevent and minimize the adverse events related to the misplacement of epidural catheters.