Chest trauma remains the major initiating cause of respiratory failure in the trauma patient. The degree of injury can be substantially modified with appropriate early preventive and treatment measures. The lung injury itself can be divided into early and late phases. The early phase is primarily the result of mechanical forces transmitted to the chest. Initial management should focus not just on the lung; there should also be a search for commonly present, associated, nonpulmonary injuries. Optimizing early restoration of perfusion is also crucial in the multiple trauma patient, instead of too "wet" or too "dry." The most complex phase is the late phase resulting from the host inflammatory response to injury, both local and systemic. Stress modification and control of inflammation are the keys to controlling this aspect of the disease process.