From June 2004 to October 2007, 34 patients with chronic heart failure and low ejection fraction underwent surgical revascularization; 23 received bypass grafting plus transplantation of bone marrow-derived stem cells (study group) and 11 had revascularization only (control group). The stem cells were implanted into nonviable myocardial areas, bypass grafting was performed in viable myocardial areas. In the study group, the ejection fraction increased from the baseline 26.4% ± 4% to 37.3% ± 11.5% after 26 months. In the control group, ejection fraction increased from 29% ± 2% to 31.5% ± 4.3% after 27 months. The improvement in the study group was significantly greater than that in the control group. Functional class improved significantly from 3.2 to 1.2 in the study group vs. 3.0 to 2.3 in the control group. Stem cell transplantation associated with bypass grafting is feasible and safe in patients with chronic heart failure with low ejection fractions, and it improves ventricular systolic function and functional class. © SAGE Publications 2010.