We report the first case of abscess formation after combined spinal-epidural block (CSE). Penetration of the dura in CSE may constitute an additional risk of subarachnoid spread of bacteria when post-puncture epidural infection is present.The combination of a spinal and a continuous epidural block (CSE) using a needle through needle technique was used in a 72-yr-old man for reconstructive vascular surgery of the lower limb. On the fourth postoperative day the patient demonstrated back pain, fever, and exudation of pus from the CSE-puncture site. An epidural abscess was diagnosed by magnetic resonance imaging and subsequently an emergency hemiaminectomy was performed. Physical examination and surgery did not show evidence of bacterial spread into the subarachnoid space.Epidural abscess formation after CSE may increase the risk of bacterial spread into the subarachnoid space. In this case spontaneous exudation and surgical drainage of abscess material may have prevented intrathecal infection. Rapid diagnosis and treatment of an epidural abscess appears particularly essential after CSE to prevent neurological sequelae.