Dilated cardiomyopathy as the most common form of cardiomyopathy is a rare but life-threatening disorder in children. The primary cause of nearly 37 % of children with DCM was unknown at diagnosis. Despite of the developing in the medical and surgical treatment during the past several decades, standard treatments (including Digitalis, diuretics, inhibitors of ACE, beta blockers, antiplatelet drugs and treatments Antiarrhythmic), may stabilize the condition, but will not restore heart function to its previous condition. Therapy remains complex and expensive. For some not all children the heart transplantation is only option and mortality continues to be high, also. Stem cell and cell-based therapies offer an innovative approach to reverse cardiac structure and function towards normal, possibly reducing the need for aggressive therapies and cardiac transplantation. According to the inclusion and exclusion criteria of trial, 32 patients with left ventricular ejection fraction less than 45% who resistance to the standard medical therapy were randomly allocated in 2 groups including BM-derived mononuclear (n=16) and control (n=16). Only the MNC group underwent the bone marrow aspiration and intracoronary injection. The investigators followed all of patients at 2 weeks, 1, 2, 4 and 6 months after transplantation for cell therapy group or registration for placebo by physical examination, laboratory tests and imaging such as echocardiography, CXR and CMR.