We report a case of accidental epidural injection of vecuronium during cholecystectomy in a 55-year-old man (63 kg, 158 cm). Following 3 ml of lidocaine 1% as an epidural test dose, inadvertent epidural (T7-8) injection of vecuronium 4.25 mg instead of ropivacaine occurred. After immediate removal of the syringe containing vecuronium, 10 ml of ropivacaine 0.375% was injected epidurally. Intubation was performed under propofol infusion using a target-controlled infusion system with intravenous vecuronium 10 mg. There was a 3 min interval between inadvertent epidural and intravenous injection of vecuronium. Anesthesia was maintained with propofol infusion (2.6-3.0 microg x ml(-1)) titrated to maintain bispectral index between 35-55 and buprenorphine 0.16 mg with 40% oxygen in air. T1 response in the train-of-four (TOF) appeared 87 min after epidural vecuronium injection. Ten minutes later, additional vecuronium 0.5mg was required due to bucking. Seven minutes after that, T1 in the TOF reappeared and the operation was finished. Twenty-three minutes after the additional vecuronium, 4 responses in the TOF were obtained. Following reversal with atropine 1.0 mg and neostigmine 2.0 mg, the patient was able to sustain head lift and handgrip, and to protrude the tongue fully awake. The patient was extubated 124 min after epidural vecuronium injection. There was no memory of back pain during epidural vecuronium injection. There was no postoperative respiratory insufficiency or neurological disorder. We suspect the duration of action of epidural vecuronium is approximately twice that of intravenous injection and becomes prolonged with higher doses and advanced age.