A 47 year-old woman, on hemodialysis via an arteriovenous (AV) fistula, was assessed for severe dyspnea and presyncope secondary to pulmonary hypertension. Right heart catheterization confirmed a mean pulmonary arterial pressure of 85 mm Hg. She had a normal wedge pressure. Investigations revealed that the total high cardiac output AV fistula, 8.3 L/min, resulted in pulmonary arteropathy and increased pulmonary vascular resistance at 674 dyne.sec.cm-5. The AV fistula was banded and Sildenafil was prescribed, which resulted in improvement of pulmonary hypertension within one week.