We encountered a case of severe acute respiratory distress syndrome in late pregnancy due to influenza (H1N1) with refractory hypoxemia to conventional mechanical ventilation. Ventilation in prone position rescued this patient by maintaining oxygenation and sustaining improvement thereafter. Here, we discuss the mechanism of prone ventilation with special references to safety management of acute respiratory distress syndrome in the third trimester of pregnancy. It requires frequent monitoring of possible complications due to prone position and highly dedicated supporting staffs. More data are required on safety of proning in the late pregnancy.