Heart failure is the state whereby the heart fails to adequately function to meet the metabolic needs of the body. The clinical signs, may or may not be found, depend on the severity of disease. Symptoms are varied from decrease activity level, exercise intolerance, dyspnea, lethargy, syncope and sudden death. The primary function of L-carnitine is mitochondrial transport and subsequent beta-oxidation of long-chain fatty acids, which are quantitatively the most important energy-producing substrate of the myocardium and skeletal muscle. Additional important functions of L-carnitine include decrease level of TNF-alpha and sphingosine that induced apoptosis, increase coronary blood flow and myocardial oxygen consumption and antiosicant. Therefore, L-carnitine appears to possess potential therapeutic benefits for the long-term treatment of patients with heart failure attributable to dilated cardiomyopathy and ischemia, which in turn helps improving cardiac function and life expectancy as well as reducing mortality rate.