Background: Idiopathic pulmonary fibrosis(IPF)is often associated with elevations in pulmonary artery pressures. Although primary pulmonary arterial hypertension (PAH) has been associated with primary graft dysfunction (PGD), the role of secondary PAH in mediating PGD risk in patients with IPF is incompletely understood. The purpose of this study was to evaluate the relationship between mean pulmonary artery pressure(mPAP)and PGD among patients with IPF. Methods: We performed a multicenter prospective cohort study of 126 lung transplant procedures performed for IPF between March 2002 and August 2007. The primary outcome was grade 3 PGD at 72 h after lung transplant. The mPAP was measured as the initial reading following insertion of the right-sided heart catheter during lung transplant. Multivariable logistic regression was used to adjust for confounding variables. Results: The mPAP for patients with PGD was 38.5 ± 16.3 mm Hg vs 29.6 ± 11.5 mm Hg for patients without PGD (mean difference, 8.9 mm Hg [95% CI, 3.6-14.2]; P =.001). The increase in odds of PGD associated with each 10-mm Hg increase in mPAP was 1.64 (95% CI, 1.18-2.26; P =.003). In multivariable models, this relationship was independent of confounding by other clinical variables, although the use of cardiopulmonary bypass partially attenuated the relationship. Conclusions: Higher mPAP in patients with IPF is associated with the development of PGD. © 2011 American College of Chest Physicians.