Acute or adult respiratory distress syndrome (ARDS) contributes to mortality and morbidity in the intensive care environment. Appropriate application of microprocessor-controlled mechanical ventilatory support, pathophysiology of the disease, and new pharmacologic modalities are currently being investigated. Mechanical ventilation is usually begun when respiratory failure is caused by alveolar hypoventilation or hypoxia. Primary choices for this therapy are control-mode ventilation, assist-control ventilation, pressure-control ventilation, intermittent mandatory ventilation, and synchronized intermittent mandatory ventilation with the addition of positive end-expiratory pressure. Patients who deteriorate despite these interventions may require alternative modes of ventilation. Pharmacologic agents in ARDS is important due to the multifactorial pathophysiologic and pharmacodynamic processes that are part of the disease. Clinical studies will continue to determine advantageous agents. Unfortunately, no convincing data exist that any pharmacologic or nonpharmacologic strategy is superior for the support of these patients or results in a better outcome than others.