In the last 15 years, heart cell implantation to regenerate infarcted myocardium has gone from the bench to clinical trial. Several phase I and II controlled randomized trials showed the feasibility, the side effects and the potential efficacy of cell implantation after myocardial infarction in humans. Preclinical experiments investigating the mechanisms of heart function improvement after cell implantation showed controversial results regarding implanted cell differentiation into cardiomyocytes and highlighted other effects including neovascularization and modifications of the extra cellular matrix remodelling. Ongoing clinical and experimental studies should pave the way for cell implantation to become a therapeutic option to prevent and treat post-myocardial infarction congestive heart failure in a near future.