Myocardial infarction is a major cause of morbidity and mortality in developed countries. Heart transplantation is an effective therapeutic modality in reconstituting the heart function. However, widespread application of this modality is severely limited due to the scarcity of organ donors and complications associated with immune suppressive regimens. Cell therapies aiming at replacing damaged heart muscle are highly desirable. Embryonic stem cells (ESCs) can serve as an inexhaustible source of cellular material for repairing infarcted myocardium. We have explored methodologies for the cardiogenic differentiation of ESCs. Furthermore, committed cells were characterized for biochemical and functional attributes akin to those of native cardiac muscle cells. Stem cells were coaxed to organize into embryoid bodies (EBs) in suspension while treated with agents known to stimulate heart cell commitment. More than 70% of the EBs formed contractile foci, indicative of cardiac mesoderm differentiation. Compared to undifferentiated ESCs, these cells transcribed heart cell-specific genes such as atrial natriuretic factor (ANF) (2.1±0.7 fold), Nkx2.5 (2.8±0.5 fold), and GATA4 (94.6±16.2 fold) as assessed by quantitative PCR. Downregulation of stem cell markers such as Rex1 (~100-fold lower compared to undifferentiated cells) was observed in differentiated cells. Protein expression was also examined by immunostaining. ESC-derived cells displayed immunoreactivity for cardiac troponin I (cTnI), cardiac transcription factor Nkx2.5, and α-actinin. Furthermore, assays were carried out to assess the functional characteristics of committed cells compared to native myocardial cells. Differentiated cells responded to treatments with pharmacological stimuli known to modulate the contractility of normal cardiomyocytes. For example, treatment with a phosphodiesterase inhibitor, increased the beating rate of these cells in a dose-dependent manner suggesting that a cAMP-dependent mechanism mediates the observed pulsating of cells. Efforts to improve the differentiation efficiency and to scale up the production of cardiomyocytes from stem cells will be discussed. These findings are expected to shed light on the mechanisms governing stem cell commitment towards cardiac cells as well as to contribute in the development of processes for the generation of engineered heart cells in clinically relevant quantities.