The heart derives its predominant energy from mitochondrial oxidation of long chain fatty acids. Carnitine, a low molecular weight amino-acid derivative, is essential for the transport of long chain fatty acids across the mitochondrial membrane to the site of beta oxidation. These fatty acids are the precursor of energy for the heart. L-Carnitine deficiency leads to a specific form of dilated CM and the aim of the present study: To assess the effect of L-carnitine in patients with dilated and or ischemic cardiomyopathy.Patients & Methods: 80 pts (56 M & 24 F) with dilated CM (Idiopahic 50 pts, ischemic 30 pts) were included in the study. They were divided into 2 groups of (forty pts each). Group I patients were treated with conventional therapy and additional L-carnitine orally administered at a daily dose of 3 gm divided in 3 doses. Serum carnitine was measured before the start of therapy and at 2, 4 and 6 months later. Group II patients were treated with conventional antifailure therapy only. Pts were followed up clinically & by 2D Echo. Echo parameters assessed included: Left ventricular end diastolic dimension (LVEDD), Left ventricular end systolic dimension (LVESD), Fraction shortening (FS), Ejection fraction (EF). Patients in group I were classified into responders and non responders. Responders were patients who showed improved outcome as regards clinical data echo parameters namely EF & LVEDD.Results: At the end of 2 months, one patient in group I died out of severe heart failure. Out of the remaining 39 carnitine treated pts, 28 pts exhibit greater in LVEDD as compared to group II patients (5.7+0.47 vs 5.87+0.46, P: 0.0001), and significantly greater increase in ejection fraction as compared to group II (39.3+8.06 vs 33.52+4.89, P: 0.0001). At the end of 4 months 22 pts out of 28 pts exhibited sustained improvement and 6 pts continued to improve with significantly decrease in LVEDD as compared to group II (5.78+0.48 vs 5.8+0.44, P: 0.0001), and significant increased in EF as compared to group II (40.3+8.02 vs 34.07+5.31, P: 0.0001).Conclusion: As a metabolic supplement the early administration of L-carnitine plus conventional anti-failure measures to patients with cardiomyopathy provides a significant improvement as regards clinical signs of heart failure and echo parameters namely EF & LVEDD with consequent improvement in quality of life for these patients. However larger scale study and longer periods is recommended to assess the long term the efficacy of L-carnitine in patients with cardiomyopathy.