OBJECTIVE Pulmonary arterial hypertension (PAH) remains challenging to treat, especially in association with scleroderma. We examined survival rates among patients with PAH in association with scleroderma who received epoprostenol (Flolan) through continuous intravenous (i.v.) infusion in an uncontrolled open-label 3-year extension study following an initial randomized, controlled 12-week study. METHODS One hundred two patients diagnosed with PAH in association with scleroderma who received epoprostenol were included in the analyses. This included 51 PAH patients from a subject population of 56 who received epoprostenol in the randomized controlled study, and 46 patients from an initial population of 55 subjects on conventional therapy in the randomized controlled study, who received epoprostenol in the extension study. All patients in this extension study received open-label epoprostenol. Adverse events, survival, and dosing information were collected throughout the study. RESULTS The probabilities of survival during the first and second years for all subjects who received epoprostenol during the initial randomized controlled study or during the extension study were 0.71 and 0.52, respectively. This measure remained constant at 0.48 during the third and fourth years. CONCLUSIONS This study reports longterm survival rates for patients with scleroderma-associated PAH treated with i.v. epoprostenol. Although comparisons to historical data should be made with caution, this study reports a better survival outcome than natural history data on patients with scleroderma-associated PAH.