Treatment of arterial pulmonary hypertension with epoprostenol (intravenous prostacyclin) improves survival and quality of life, but the need for an implanted central venous catheter is associated with frequent complications, that often (as in the case of infection or dislodgment) are serious and require catheter replacement. Treprostinil is a prostacyclin analogue suitable for continuous subcutaneous administration. We report the successful transition from intravenous epoprostenol to subcutaneuos treprostinil in four patients with severe pulmonary hypertension who suffered from serious complications associated with the epoprostenol infusion system.