Background: Clinical outcome after unplanned extubation (UE) in patients admitted to the surgical intensive care unit (SICU) has not been fully investigated. In this study we assessed in-hospital mortality of patients with UE and determined whether UE is a predictor of in-hospital mortality. Finally, we sought to identify predictors of reintubation after UE in mechanically ventilated patients in the SICU. Methods: Medical charts of patients (n = 4,407) admitted to the SICU between October 2007 and December 2011 were reviewed retrospectively. Results: Eighty-five episodes of UE occurred in 81 patients. Patients with UE required emergency surgery more frequently and had higher ICU and hospital mortality rates, reintubation rate, and APACHE II scores and longer mechanical ventilation (MV) and ICU stay than patients without UE (P < 0.05 for all associations). Multivariate analysis revealed that reintubation (odds ratio [95 % confidence interval]: 4.14 [2.58-6.67]; P < 0.001), APACHE II scores (1.14 [1.12-1.17]; P < 0.001), emergency surgery (1.73 [1.18-2.53]; P = 0.005), and chronic neurologic disease (2.11 [1.30-3.41]; P = 0.002) were associated with hospital mortality. Reintubation was necessary in 17 patients. On multivariate analysis, a score on the Richmond Agitation-Sedation Scale (RASS, 0.48 [0.31-0.76]; P = 0.001), PaO2/FiO2 ratio (0.99 [0.99-1.00]; P = 0.048), and MV duration before UE (1.46 [1.08-1.98]; P = 0.014) were independently associated with reintubation after UE. Conclusions: Our results indicated that although patients with UE had high in-hospital mortality, UE was not directly associated with in-hospital mortality. Reintubation, chronic neurologic disease, emergency operation, and higher APACHE II score were related to increased in-hospital mortality. A low RASS score, a low PaO2/FiO2 ratio, and long MV duration before UE were related to reintubation after UE.