We studied the phenotype and cytokine production in peripheral blood mononuclear cells mobilized from the bone marrow after administration of granulocyte colony-stimulating factor (G-CSF) and the relationship of these parameters with clinical efficacy of autologous intramyocardial injection of donor cells in patients with chronic heart failure. We found that mononuclear cells contain endothelial progenitor cells and are capable of producing pleiotropic cytokines exhibiting angiogenic and cardioprotective properties. High concentration of cells with of CD34+ and CD34+/CD133+ phenotype in the cell transplant and enhanced production of IL-10, TNF-α, and granulocyte-macrophage-CSF by blood mononuclear cells mobilized from the bone marrow can contribute to improvement of myocardial perfusion and increase in left ventricular ejection fraction after intramyocardial transplantation and can serve as predictors of high efficiency of cell therapy. Peripheral blood is an available source of progenitor cells, while mononuclear cells after administration of granulocyte-CSF can produce a reparative effect on ischemic myocardium.