We have reported a case of right upper limb injury of shoulder and elbow who was managed with ultrasound-guided interscalene block during surgery and indwelling catheter for postoperative analgesia. He developed weakness in the contralateral upper limb in the postoperative period due to inadvertent spread of local anaesthetic in the cervical epidural space. No serious complication occurred due to timely intervention. The possible pathways of such unwanted epidural spread and methods to reduce such complications have been discussed.