Purpose There have been few reports on the risk factors for tracheostomy and the possibility of patients for decannulation. The purpose of this study was to identify factors necessitating tracheostomy after cervical spinal cord injury (SCI) and detect features predictive of successful decannulation in tracheostomy patients. Methods One hundred and sixty four patients with cervical fracture/dislocation were retrospectively reviewed. The patients comprised 142 men and 22 women with a mean age of 44.9 years. The clinical records were reviewed for patients' demographic data, smoking history, level of cervical spine injury, injury patterns, neurological status, evidence of direct thoracic trauma and head injury, tracheostomy placement, and decannulation. Risk factors necessitating tracheostomy and factors predicting decannulation were statistically analysed. Results Twenty-five patients (15.2 %) required tracheostomy. Twenty-one patients were successfully decannulated. Smoking history (relative risk [RR], 3.05; p = 0.03) and complete SCI irrespective of injury level (C1-4 complete SCI: RR, 67.55; p \ 0.001, C5-7 complete SCI: RR, 57.88; p \ 0.001) were significant risk factors necessitating tracheostomy. C1-4 complete SCI was more frequent among those who could not be decannulated. However, even in patients with high cervical complete SCI at the time of injury, patients regaining sufficient movement to shrug their shoulders within 3 weeks after injury could later be decannulated. Conclusions The risk factors for tracheostomy after complete SCI were a history of smoking and complete paralysis irrespective of the level of injury. High cervical level complete SCI was found to be a risk factor for the failure of decannulation in patients without shoulder shrug within 3 weeks after injury.