Background: Recently, experimental studies have shown improvement on left ventricular functionand reduction in infarct scar size after intracoronary injection of autologous cells derived from bonemarrow (BMC) in the acute fase of myocardial infarction. There is yet no large clinical trialsreleased about the subject, but five intermediate sized randomized trials have been published.Method: I have reviewed the five studies BOOST, Janssens et al, ASTAMI, REPAIR-AMI andREGENT, translated and somewhat summarized them before I have discussed the most importantand relevant results. To supply my findings, I have included the most relevant results from the twometa- analysis by Abdel-Latif et al. and Martin-Rendon et al.Results: To this date, it may seem that BMC treatment gives a small to moderate improvement inleft ventricular parameters as well as a reduction in infarct scar size. The results are somewhatheterogenous, but overall they seem to point in a positive direction. In the meta-analyses, BMCtherapy is found to significantly improve left ventricular ejection fraction with 3,0 – 3,6 % points.Some of the studies suggest that better results can be expected on patients with severly depressedleft ventricular function, as well as when cells are injected five or more days after the PCItreatment.Conclusion: Stem cell treatment for acute myocardial infarction is a promising, new treatmentoption. The data from the trials assessed suggest that one can achieve improvement on top ofconventional therapy, if yet only moderate. Further, adequately powered trials using optimal dosingand timing, longer term outcome assessments, more reliable and more patient-centered outcomesare required before this treatment can be considered for routine clinical use.