The presence of bilateral lung infiltrates on chest imaging is a mandatory criterion for the diagnosis of acute respiratory distress syndrome (ARDS). This retrospective single-center observational study assessed the agreement between chest radiograph interpreted by intensivists and chest computed tomography interpreted by radiologists for the diagnosis of ARDS in mechanically ventilated patients with hypoxemia. Chest CT was considered the reference standard. The study evaluated interobserver agreement and diagnostic performance of chest radiography in the overall population and in predefined subgroups.