Diastolic heart failure with hypoxemia is a dangerous condition in pregnancy for both the mother and the fetus. Continuous positive airway pressure may help to decrease afterload and reduce venous return and ventricular filling, but its use in diastolic dysfunction has not yet been established. The authors report a case of a patient with pregnancy-induced hypertension and oligohydramnios who developed acute decompensated diastolic heart failure. The addition of continuous positive airway pressure, diuretics, and neurohormonal-blocking agents lead to a dramatic clinical and physiologic improvement. The authors recommend consideration of the use of positive pressure ventilation in these patients.