OBJECTIVES: The patients with head injury usually develop respiratory failure under mechanical ventilator support. This research was to evaluate the impact of tracheostomy on the in hospital mortality for these patients after liberation from mechanical ventilator. METHODS: A retrospective cohort study was designed for this research. The clinical data of of subacute respiratory care center (RCC) of Chimei Medical Center, Taiwan was evaluated from January, 2012 to October, 2017. The data of age (18 to 70 years old), gender, Acute Physiology and Chronic Health Evaluation (APACHE II) score, blood urea nitrogen (BUN) (mg/dL), creatinine(mg/dL), albumin (mg/dL), phosphate (mg/dL) , hemodialysis, tracheotomy performance or not, and in hospital mortality were evaluated for this study. The SPSS for windows17.0 was used to analyze the patient's data, in-depending T test and Chi-square were analyzed for the mortality outcome of these patients after liberation from mechanical ventilator for the two cohorts (tracheotomy performance or not). RESULTS: A total of 212 cases were enrolled in this study, included tracheostomy cohort (N=90) and without tracheostomy cohort (N=111). Clinical data of these patients’ age, gender, and blood biochemical tests (BUN, creatinine, albumin, phosphate levels) showed no significant different between the two cohorts. The clinical in hospital mortality in tracheostomy cohort is lower than the cohort without tracheostomy (mortality rate; 3.2% Vs 6.7%, P > 0.05) but without reaching significant difference. High RCC APACHE II scores related with significant high in hospital mortality rate of these patients after weaning from ventilator (12.66 ± 0.349 Vs 17.6 ± 1.127, P < 0.05) CONCLUSIONS: Low in hospital mortality rate was found for these patients with tracheostomy after liberation from mechanical ventilator. High RCC APACHE II scores related with the in hospital mortality rate