It is often unclear when and how to wean patients from mechanical ventilation. We have devised an evidence-based protocol in which patients undergo a 30-minute trial of spontaneous breathing with a T tube or pressure support of 7 cm H2O. Those who can tolerate the trial are extubated, while those who cannot are reconnected to mechanical ventilation but undergo another trial every day until they can be extubated. More study is needed to improve the criteria to predict successful spontaneous breathing and extubation, and to clarify the role of non-invasive ventilation to avoid reintubation.