When treated with invasive endotracheal mechanical ventilation (ETMV), acute respiratory insufficiency after lung resection is fatal in up to 80% of cases. Noninvasive positive-pressure ventilation (NPPV) may reduce the need for ETMV, thereby improving survival. We conducted a randomized prospective trial to compare standard therapy with and without nasal-mask NPPV in patients with acute hypoxemic respiratory insufficiency after lung resection. The primary outcome variable was the need for ETMV and the secondary outcome variables were in-hospital and 120-d mortality rates, duration of stay in the intensive care unit, and duration of in-hospital stay. Twelve of the 24 patients (50%) randomly assigned to the no-NPPV group required ETMV, versus only five of the 24 patients (20.8%) in the NPPV group (p = 0.035). Nine patients in the no-NPPV group died (37.5%), and three (12.5 %) patients in the NPPV group died (p = 0.045). The other secondary outcomes were similar in the two groups. NPPV is safe and effective in reducing the need for ETMV and improving survival after lung resection.