Background: unplanned extubation (UE), which is defined as deliberate self-extubation by a patient receiving mechanical ventilation support or accidental extubation by staff nursing and medical procedures. Objective: assess the effect of accidental and selfextubation on mechanically ventilated patients' outcomes. Design: a descriptive research design was used in this study. Research question: what is the effect of accidental and self-extubation on mechanically ventilated patients' outcomes? Setting: This study was conducted in general and trauma intensive care units at Assuit University Hospital. Subjects: sixty critically ill patients attached with the endotracheal tube and mechanical ventilation Results: the majority of the studied critically ill patient had respiratory consequences after UE and statistically significant differences between self-extubation and accidental extubation patients regarding occurrences of aspiration and tachycardia on the first day. Conclusion: Unplanned extubation (UE) is a frequent event after endotracheal intubation with mechanical ventilation (MV). Self-extubation is the most common type of UE and accidental removal of the tube is a very poor patient outcome and needs more aggressive management than patients with self-extubation.