In the era of proton-antiproton collisions, stem cell field has emerged as the newly recognized protons of regenerative medicine. Great interest and enthusiasm were depending on their behavioral difference such as self-renewal, clonogenicity and differentiation into functional progeny that may become vehicles for regenerative medicine. Although progress has evolved dramatically strategies using stem-cell-driven cardiac regeneration involve extremely complex and dynamic molecular mechanisms. Cell death in transplanted heart continues to be a significant issue. Every step from stem cell homing, and migration to retention, engraftment, survival and differentiation in cardiac cytotherapy deserves intense research for optimum results. Furthermore, regeneration of contractile tissue remains controversial for human studies and careful interpretation is warranted for modest benefit in clinical trials. Currently, the only realistic approach to replace the damaged cardiomyocytes is cardiac transplantation for patients with end-stage heart failure. Ultimately, the giant footsteps in cell-based cardiac repair can only be achieved by an enthusiastic but also skeptical teams adhering to good manufacturing practices. Better understanding of cell-fate decisions and functional properties in cardiac cytotherapy may change the erosion of initial enthusiasm and may open new prospects for cardiovascular medicine.