Diastolic heart failure is defined clinically when signs and symptoms of heart failure are present in the presence of preserved left ventricular systolic function (ejection fraction >45%). The incidence and prevalence of primary diastolic heart failure increases with age and it may be as high as 50% in the elderly. Age, female gender, hypertension, coronary artery disease, diabetes, and increased body mass index are risk factors for diastolic heart failure. Hemodynamic consequences such as increased pulmonary venous pressure, post-capillary pulmonary hypertension, and secondary right heart failure as well as decreased cardiac output are similar to those of systolic left ventricular failure, although the nature of primary left ventricular dysfunction is different. Diagnosis of primary diastolic heart failure depends on the presence of preserved left ventricular ejection fraction. Assessment of diastolic dysfunction is preferable but not mandatory. It is to be noted that increased levels of B-type natriuretic peptide does not distinguish between diastolic and systolic heart failure. Echocardiographic studies are recommended to exclude hypertrophic cardiomyopathy, infiltrative heart disease, primary valvular heart disease, and constrictive pericarditis. Myocardial stress imaging is frequently required to exclude ischemic heart disease. The prognosis of diastolic heart failure is variable; it is related to age, severity of heart failure, and associated comorbid diseases such as coronary artery disease. The prognosis of severe diastolic heart failure is similar to that of systolic heart failure. However, cautious use of diuretics and/or nitrates may cause hypotension and low output state. Heart rate control is essential to improving ventricular filling. Pharmacologic agents such as angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers are used in selected patients to decrease left ventricular hypertrophy. To decrease myocardial fibrosis, aldosterone antagonists have a potential therapeutic role. However, prospective controlled studies will be required to establish their efficacy in primary diastolic heart failure.