In the past few years, significant advances have been performed in the field of cell-based therapies. This concerns mainly regenerative medicine with the use of stem cells, as well as the modulation of immune responses. In order to modulate allogeneic immune responses after transplantation, we have developed a cell therapy approach based on the immunomodulatory properties of intravenous donor apoptotic cell infusion. In allogeneic hematopoietic cell transplantation settings, we reported that intravenous apoptotic leukocyte infusion, simultaneously to allogeneic bone marrow grafts, favors hematopoietic engraftment, prevents alloimmunization and delays graft-versus-host disease. Here, we review the different factors and cells implicated in the immunomodulatory properties of apoptotic cells. Then, we discuss the potential significance of such observations in transfusion practice.