The syndrome of congestive heart failure with preserved left ventricular systolic function is common in clinical practice. The signs and symptoms of the disorder are similar to those of congestive heart failure with left ventricular systolic dysfunction, underscoring a need for routine evaluation of left and right ventricular systolic function in patients with congestive heart failure. The syndrome may be related to anatomic abnormalities that increase the resistance to ventricular filling, or to physiologic abnormalities of myocardial relaxation or compliance. Advancing age, often in association with hypertension, coronary artery disease, tachycardia, and atrial fibrillation, is commonly associated with the disorder. Randomized controlled clinical trials are needed to evaluate the efficacy of various therapeutic agents in reducing the risks associated with diastolic heart failure.