Background Cardiac rehabilitation (CR) is recommended to patients with chronic heart failure (CHF) and reduced Left-Ventricular ejection fraction (EF) at a class 1 evidence level. Purpose The aim of this prospective study was to assess the effect of a rehabilitation program on EF in patients with CHF. Methods One hundred and five patients (mean age: 5713 years, men: 67%, diabetic patients: 42%) with CHF (EF Reasons of admission were: coronary heart disease artery bypass graft surgery (17%), angioplasty percutaneous coronary interventions and stent (24%), angor pectoris or myocardial infarction (8%), aortic or mitral valve replacement or repair (10%), dilated cardiomyopathy (34%), other (7%). Patients received beta-blocker (96%), conversion enzyme inhibitor or angiotensine II receptor antagonist (42%), sacubitril-valsartan (48%), furosemide (60%), antialdosterone therapy (55%), ivabradine (12%), other (11%). EF assessed by echocardiography using the biplane Simpson's method, peak oxygen consumption (VO2), maximal walking distance (MWD) during 6 min walk test and NT-proBNP were assessed before and after rehabilitation. Results After 6 weeks, there were significantly improvements in EF (35% ± 7.23 vs. 40% ± 8.3 - P Conclusion Our study shows that a 6-week multidisciplinary tailored Cardiac Rehabilitation Program improves significantly Left-Ventricular ejection fraction in patients with Chronic Heart Failure. This should be relevant to improve prognosis.