Respiratory failure affects up to 1 in 500 pregnancies, more commonly in the postpartum period. The causes of respiratory failure include several pregnancy-specific conditions such as preeclampsia, amniotic fluid embolism, and peripartum cardiomyopathy. Pregnancy may also increase the risk or severity of other conditions, such as asthma, thromboembolism, viral pneumonitis, and gastric acid aspiration. Changes to maternal respiratory physiology and the presence of a fetus may affect the assessment and management of these patients. In addition to identifying pregnancy-specific causes, some differences exist in the management of the pregnant woman with acute respiratory failure. Endotracheal intubation in pregnancy carries a significant risk, due to upper airway edema and rapid oxygen desaturation following apnea. Few studies have addressed prolonged mechanical ventilation management in pregnancy. Optimizing oxygenation is important, but whether permissive hypercapnia is tolerated during pregnancy remains unclear. Delivery of the fetus is often considered but does not always improve maternal respiratory function and should be reserved only for cases where benefit to the fetus is anticipated.