Acute lung injury (ALI) is a form of acute respiratory failure, defined by hypoxemia and the presence of bilateral infiltrates on chest radiograph, and often referred to by its most severe subset known as acute respiratory distress syndrome (ARDS). ALI occurs in approximately 200,000 people each year in the U.S. and in some centers occurs in more than 25% of mechanically ventilated patients. There are various inciting causes for ALI and ARDS which have the common theme of oxidative stress and inflammation, producing an acute inflammatory lung disease with consequent abnormal alveolar-capillary permeability and proteinaceous pulmonary edema, and clinically manifest as hypoxemia, reduced lung compliance and respiratory failure requiring mechanical ventilation. Our clinical critical care research group has been involved in ALI/ARDS research for more than a decade, and we have an active screening process to identify ALI/ARDS patients for inclusion in an ongoing registry. We have investigated aspects of ALI/ARDS varying from epidemiology to predictive and prognostic biomarkers and genetic polymorphisms to treatment interventions.