Rationale: Pulmonary arterial hypertension (PAH) is a rare progressive disease of the pulmonary vasculature that is characterized by endothelial dysfunction, inflammation, and right ventricular dysfunction. Objectives: The main objective was to determine whether endothelial, inflammatory, and cardiac biomarkers would be associated with the World Health Organization functional assessment and survival in patients with PAH. Methods: We performed a retrospective cohort study of patients with PAH enrolled in the Randomized Clinical Trial of Aspirin and Simvastatin for Pulmonary Arterial Hypertension (ASA-STAT). Biomarkers (N-terminal fragment of pro-BNP [NT-pro-BNP], von Willebrand factor [vWF], soluble P selectin, C-reactive protein, total and high-density lipoprotein cholesterol, triglycerides, tumor necrosis factor, IL-6, β-thromboglobulin, and thromboxane B2) were measured at baseline. Patients from the study were followed until lung transplantation, death, or August 1, 2013. Ordinal logistic regression and Cox regression analyses were performed. Measurements and Main Results: Sixty-five patients with PAH were enrolled. The mean age was 51 years, and 86% were women. Higher vWF activity, lower high-density lipoprotein cholesterol, and higher thromboxane B2 levels were associated with worse World Health Organization functional class after adjustment for age, sex, and etiology of PAH. Higher NT-pro-BNP levels, lower vWF activity, and lower total cholesterol were associated with an increased risk of death or lung transplant after adjustment for age, sex, etiology of PAH, and 6-minute-walk distance. Conclusions: In patients with PAH, lower vWF activity and cholesterol levels and higher NT-pro-BNP levels at baseline were associated with an increased risk of death or transplantation. Clinical trial registered with www.clinicaltrials.gov (NCT00384865).