OPINION STATEMENT: Despite the development of several injectable or oral treatments for relapsing-remitting multiple sclerosis (RRMS), it remains difficult to treat patients with aggressive disease, and many of these continue to develop severe disability. During the last two decades autologous hematopoietic stem cell transplantation (aHSCT) has been explored with the goal to eliminate an aberrant immune system and then re-install a healthy and tolerant one from hematopoietic precursor cells that had been harvested from the patient prior to chemotherapy. Clinical studies have shown that aHSCT is able to completely halt disease activity in the majority of patients with aggressive RRMS. Research on the mechanisms of action supports that aHSCT indeed leads to renewal of a healthy immune system. Below we will summarize important aspects of aHSCT and mention the currently best-examined regimen.