Objective: To determine the prevalence of right and left ventricular dysfunction in a prescreened population of patients with severe pulmonary disease, and to analyze the relationship between right and left ventricular function, Design: Retrospective record review of 434 patients with severe pulmonary disease. Patients: Patients with end-stage pulmonary disease, including alpha(1)-antitrypsin deficiency emphysema, COPD, cystic fibrosis (CF), idiopathic pulmonary fibrosis, and pulmonary hypertension (primary and Eisenmenger's syndrome), who were evaluated for lung transplantation between January-1993 and December 1995, Measurements: Pulmonary function tests, arterial blood gases, radionuclide ventriculography, two-dimensional transthoracic echocardiography, pulmonary hemodynamics, coronary angiography. Results: Right ventricular dysfunction (right ventricular ejection fraction [RVEF] <45%) was present in 267 patients (66%), but the prevalence was highest (94%) in patients with pulmonary vascular disease. Among the patients with airway or parenchymal lung disease, the prevalence ranged fron? 59% in COPD to 66% in CF. In contrast, left ventricular dysfunction (left ventricular ejection fraction [LVEF] <45%) was present in only 6.4%, but it, too, was most common in the group with pulmonary hypertension (19.6%). In the groups with parenchymal or airway disease, the prevalence was 3.6%, and there was no statistical difference among the four diagnoses (alpha(1)-antitrypsin deficiency emphysema; COPD; CF; idiopathic pulmonary fibrosis), LVEF showed a significant correlation with RVEF (r=0.44; P<0.05), and left ventricular dysfunction was associated with tie presence of moderate-to-severe tricuspid regurgitation but not with coronary artery disease. In a subset of patients with both right and left ventricular dysfunction who subsequently underwent lung transplantation, RVEF and LVEF increased pari passu after transplantation, Conclusion: The prevalence of right ventricular dysfunction is high in patients with end-stage pulmonary disease, but the prevalence of left ventricular dysfunction is relatively low. Left ventricular dysfunction appears to be related to right ventricular dysfunction, perhaps through ventricular interdependence.