AIM AND OBJECTIVE: To discuss the factors leading to self-extubation of endotracheal tubes (ETTs) and explore the differences between the groups of patients who did and did not self-remove their ETTs. BACKGROUND: Self-extubation of ETTs has been reported to occur in 4.2% of severely ill patients and is associated with adverse medical effects. DESIGN: A case-control study. METHODS: One hundred and thirty-nine subjects were recruited from a teaching hospital in southern Taiwan based on purposive sampling. The rate of self-extubation of ETTs was 6.4%. Analysis of the two groups demonstrated that significant variables were identified and fell into three categories: (1) the department to which the patient was admitted (p < 0.001), (2) whether the patient met the criteria for extubation (p < 0.001) and (3) the patient age (p < 0.05). Based on multiple logistic regression analysis, whether the patient met the criteria for extubation was a main variable that was associated with self-extubation of the ETT. Among the 44 patients who had self-extubation of their ETT, 28 met the criteria to be extubated, 70% and 81.8% of whom were not sedated, and self-extubation of their ETT was conscious of the act. Of the patients who attempted to self-remove their ETT, 80% were successful and 93.2% did not incur any adverse medical effects. CONCLUSION: The medical doctor and nurse should fully evaluate a patient's oxygenation status, decrease the length of the extubation training session for patients and extubate patients promptly when extubation criteria are met. RELEVANCE TO CLINICAL PRACTICE: Adopting a proactive approach to patient extubation will improve the overall quality of care.