Mobilized peripheral blood progenitor cells (PBSC) are increasingly being used instead of bone marrow for allogeneic transplantation. The purpose of the present article is to give a concise and clinically oriented overview on current results and perspectives of allogeneic peripheral blood stem cell transplantation, with particular focus on reconstitution of hematopoiesis and the immune system, graft-versus-host disease, graft-versus-leukemia effects, intensity-reduced conditioning, and graft engineering.