We studied patients with pulmonary hypertension who had evidence of bronchial responsiveness to inhaled albuterol. The records of all patients evaluated for lung transplantation were reviewed: the charts of patients with pulmonary hypertension, either primary (PPH, n = 46) or Eisenmenger's syndrome (n = 12), were abstracted. Measurements of lung function revealed equal numbers of patients with normal, restrictive, obstructive, and mixed abnormalities. None were more than moderate. Airway responsiveness was defined as an increase of forced expiratory volume in 1 second (FEV1) > 15% or forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) > 25%. Of the 24 PPH and nine Eisenmenger's patients, 14 and four, respectively, had reversible airflow obstruction. These patients were more likely to have a history of atopic disease and to have responded to calcium channels blockers during hemodynamic monitoring. They did not have more severe pulmonary hypertension, as measured by hemodynamic monitoring. Four patients had a history of asthma, which required hospitalization in three. Reversible airflow obstruction occurred in half of the patients with pulmonary hypertension and was clinically important in at least three.