The prognosis for patients with pulmonary hypertension is extremely poor. Predictors of poor prognosis among these patients include a cardiac index less than 2.8 L/m/m2, a mean pulmonary artery pressure higher than 50 mm Hg, a mean right atrial pressure more than 10 mm Hg, and PaO2 less than 70 mm Hg. Balloon atrial septostomy was performed as a palliative procedure in six patients with pulmonary hypertension to limit further deterioration while they awaited lung transplantation. The goal of balloon atrial septostomy was to increase cardiac output while limiting the reduction in systemic oxygen saturation to less than 10% of baseline. This procedure may proven to be a valuable adjunct to reduce morbidity and mortality from right ventricular failure for pulmonary hypertension candidates awaiting lung transplantation.