Theophylline has been utilized widely as a bronchodilator, but only in recent years have its positive cardiovascular effects been recognized in patients with chronic obstructive pulmonary disease. After intravenous administration of aminophylline, pulmonary artery pressures and pulmonary vascular resistance are reduced, and both right and left ventricular ejection fraction are increased. Similar short- and long-term enhancement of biventricular performance is produced by orally administered long-acting theophylline. Possible mechanisms for this theophylline-induced improvement in right and left ventricular systolic pump performance include enhanced ventricular inotropy and reduced ventricular afterload. A recent study has established that orally administered theophylline also reduces dyspnea in patients with chronic obstructive pulmonary disease. Accordingly, in patients with chronic obstructive pulmonary disease theophylline may be useful for reducing pulmonary artery pressure and pulmonary vascular resistance, treating right or left heart failure, reducing dyspnea, and partially reversing airway obstruction.