A 67-year old man with a history of cardiac disease underwent epidural catheterization for pain control of postherpetic neuralgia. Patient had severe back pain and pus discharge at catheter insertion site after dischange from medical part. Patient received anticoagulant therapy with $Aspirin^{(R)}$ and $Coumadin^{(R)}$ prescribed for 15 days in medical part. Magnetic resonance imaging(MRI) showed a diffuse $T_{4-7}$ anterior epidural mass compressing the spinal cord. Emergency surgical exploration revealed a thoracic epidural hematoma without abcess formation. Operation was successful and patient recovered satisfactory without any sequelae.