BACKGROUND: Pulmonary vascular findings are largely unreported in end-stage chronic obstructive pulmonary disease (COPD). METHODS: Pulmonary vascular lesions in explanted lungs from 70 patients with COPD/emphysema or α-1-antitrypsin deficiency were analyzed retrospectively. Patients were stratified by the presence and severity of pulmonary hypertension (PH) assessed by right-heart catheterization in 3 hemodynamically distinct groups: (1) non-PH (mean pulmonary arterial pressure [mPAP]50 mm Hg; median HE Grade 4 (range 3-6), with generalized arterial dilatation and plexiform lesions. CONCLUSIONS: The extent of pulmonary vascular lesions in COPD correlate with the severity of PH. Morphologic lesions similar to those characteristic of IPAH can be observed as PH in COPD progresses to levels characteristic of IPAH.