Intraoperative impending compartment syndrome (ICS) is an extremely rare but lethal occurrence that can involve the upper and/or lower limb(s). It commonly occurs in patients who undergo anaesthesia in various special positions such as lithotomy, lateral decubitus or prone. We present a patient who developed an ICS of his left forearm during a cervical spine surgery in prone position. This devastating condition was fortunately identified when the pulse oximetry, intra-arterial wave form and motor-evoked potentials signal disappeared abruptly from our monitors. We discuss our perioperative challenges and management for the patient which had eventually saved the patient's limb.