Heart failure with preserved ejection fraction, also referred to as diastolic heart failure, causes almost one-half of the 5 million cases of heart failure in the United States. It is more common among older patients and women, and results from abnormalities of active ventricular relaxation and passive ventricular compliance, leading to a decline in stroke volume and cardiac output. Heart failure with preserved ejection fraction should be suspected in patients with typical symptoms (e.g., fatigue, weakness, dyspnea, orthopnea, paroxysmal nocturnal dyspnea, edema) and signs (S3 heart sound, displaced apical pulse, and jugular venous distension) of chronic heart failure. Echocardiographic findings of normal ejection fraction with impaired diastolic function confirm the diagnosis. Measurement of natriuretic peptides is useful in the evaluation of patients with suspected heart failure with preserved ejection fraction in the ambulatory setting. Multiple trials have not found medications to be an effective treatment, except for diuretics. Patients with congestive symptoms should be treated with a diuretic. If hypertension is present, it should be treated according to evidence-based guidelines. Exercise and treatment by multidisciplinary teams may be helpful. Atrial fibrillation should be treated using a rate-control strategy and appropriate anticoagulation. Revascularization should be considered for patients with heart failure with preserved ejection fraction and coronary artery disease. The prognosis is comparable to that of heart failure with reduced ejection fraction and is worsened by higher levels of brain natriuretic peptide, older age, a history of myocardial infarction, and reduced diastolic function.