Aggressive forms of multiple sclerosis (MS) represent a limited group of demyelinating diseases that rapidly progress to severe disability. Currently available therapies are poorly effective against these clinical entities. Recently, it has been demonstrated that intense immunosuppression followed by autologous haematopoietic stem cell transplantation (AHSCT) can affect the clinical course of individuals with severe MS and completely abrogate the inflammatory activity detected by MRI. We report the result of the Italian phase 2 GITMO study, a multicentre study in which 21 MS patients, who were rapidly deteriorating and not responding to the usual therapeutic strategies, were treated with this procedure. The clinical effect of the treatment is long lasting, with a striking abrogation of inflammation detected by MRI findings. These results support a role for intense immunosuppression followed by ASCT as treatment in rapidly evolving MS cases unresponsive to conventional therapies.