This article discusses the potential benefits of sedation for the mechanically ventilated patient. These benefits include the alleviation of anxiety and pain, which may result in a reduction of oxygen consumption. Other advantages include improved synchronization of a patient's breathing pattern with ventilator settings and better patient care, comfort, and safety. The patient's clinical situation, such as respiratory failure caused by right-to-left shunt, cardiovascular problems, elevated intracranial pressure, hepatic disease, and renal failure, needs to be considered when selecting a sedative agent.