High-dose chemotherapy followed by autologous stem cell transplantation is an accepted form of treatment for patients with AL amyloidosis and multiple myeloma. It is not widely recognized that patients with myeloma and amyloidosis might be associated with an IgM monoclonal protein. We review the pre-transplantation characteristics and outcomes of 17 IgM amyloidosis and 8 IgM myeloma patients who underwent transplantation at Mayo Clinic from 1989 through 2008. IgM patients are older, and the amyloidosis cohort has a higher incidence of neuropathy and lower incidence of cardiac involvement by echocardiography and troponin T level.