Unplanned extubations are recurrent adverse events in mechanically ventilated children and have been the focus of quality and safety improvement in paediatric intensive care units (ICUs). To reduce the rate of unplanned extubation in the paediatric ICU by 66% (from 2.02 to 0.7). This is a quality improvement project that was conducted in a paediatric ICU of a private hospital at the quaternary level. All hospitalised patients who used invasive mechanical ventilation between October 2018 and August 2019 were included. The project was based on the Improvement Model methodology of the Institute for Healthcare Improvement to implement change strategies. The main ideas of change were innovation in the endotracheal tube fixation model, evaluation of the endotracheal tube positioning, good practices of physical restraint, sedation monitoring, family education and engagement and checklist for prevention of unplanned extubation, with Plan-Do-Study-Act, the tool chosen to test and implement ideas for change. The actions reduced the unplanned extubation rate to zero in our institution and sustained this result for a period of 2 years, totalling 743 days without any event. An estimate was made comparing cases with unplanned extubation and controls without the occurrence of this adverse event, which resulted in savings of R$955 096.65 (US$179 540.41) during the 2 years after the implementation of the improvement actions. The improvement project conducted in the 11-month period reduced the unplanned extubation rate to zero in our institution and sustained this result for a period of 743 days. Adherence to the new fixation model and the creation of a new restrictor model, which enabled the implementation of good practices of physical restraint were the ideas of change that had the greatest impact in achieving this result.