Congestive heart failure, which is most commonly caused by myocardial infarction, is the most frequent cause of hospitalization in the United States in patients over the age of 65. Although current pharmacotherapy can inhibit neurohormonal activation, this falls short of preventing left ventricular remodeling and the development of congestive heart failure. Stem cells are undifferentiated pluripotent cells that have the potential to proliferate and differentiate into cardiomyocytes. Cellular cardiomyoplasty, which is the replacement or regeneration of cardiomyocytes through cell transplantation, is a potential therapeutic approach to prevent left ventricular remodeling after myocardial infarction. The majority of the data on stem cell transplantation comes from preclinical animal studies. Although the results are interesting and perhaps safe, early phase I clinical studies are small and very preliminary. Data from large, randomized controlled trials are needed to clarify the short- and long-term effects of cellular cardiomyoplasty.