The acute respiratory distress syndrome (ARDS) is a complex disorder associated with rapidly progressive lung inflammation, non-cardiogenic pulmonary edema, hypoxemic respiratory failure and one or more well-defined risk factors including sepsis and severe trauma. Since its original description in 1967, experimental and clinical evidence has provided considerable insight into the key roles deregulated systemic inflammation and coagulation play in this devastating clinical syndrome. Despite substantial advances in our understanding of the pathogenesis of ARDS, until recently, little progress had been made in uncovering clinical strategies to improve the outcome of patients with ARDS. However, over the past 10 years protective ventilation and other supportive management strategies have been identified that markedly improve the outcome in ARDS. More recently, research has identified patients at risk for the development of the syndrome. Currently, clinical trials are underway.