Return of diaphragm function in an individual with ventilator-dependent high cervical tetraplegia is presented. The patient was maintained on a ventilator for five years after sustaining a C3-C4 vertebral fracture with a complete high cervical tetraplegia. Diaphragmatic fluoroscopic evaluation at the initial injury time revealed a nonfunctioning diaphragm, and the patient was subsequently discharged home on a portable ventilator. Respiratory evaluation 5 years post injury, including, diaphragmatic fluoroscopy, transcutaneous phrenic nerve conduction studies and pulmonary function tests, revealed intact phrenic nerve function bilaterally with spontaneous diaphragmatic motion. Subsequently, successful ventilatory weaning and diaphragmatic muscle strengthening was achieved. This case report emphasises the importance of serial evaluation of phrenic nerve viability, diaphragmatic function and ventilator dependency in patients with a high cervical tetraplegia in light of potential neurological recovery.