Stem cell therapy after acute myocardial infarction is a promising therapeutic strategy. Intermediate-sized clinical trials to answer many unanswered questions must be carefully designed and surrogate end points carefully chosen. Moreover, imaging techniques accurate enough to measure surrogate parameters and to make it possible to reduce sample size are needed. The imaging technique of choice in this setting should be capable of tracking the destiny of the stem cells once injected in the heart and of quantifying left ventricular remodelling parameters. This information will be crucial in the design of multicenter, large, randomized trials to assess survival, which can definitively establish the usefulness of this therapeutic strategy.