Antimony compounds cure kala-azar, a disease which is accompanied with an increase in the globulin content of the serum.1 Because of this association, antimony compounds have been tried in other diseases in which hyperglobulinemia occasionally occurs. These preparations have been given in Hodgkin's disease, leukemia and multiple myeloma, but until now favorable reports have not appeared in the literature. Since 1939 diamidine compounds not containing antimony have been successfully employed in the treatment of kala-azar.2 This report deals with the influence of two diamidine compounds, Stilbamidine (4,4-diamidinostilbene) and Pentamidine (4,4'-[pentamethylenedioxy]dibenzamidine),3 on multiple myeloma, a disease in which increase of the globulin content of the serum is of frequent occurrence.4 For 13 patients with multiple myeloma the administration of Stilbamidine, combined with a diet low in animal protein, has had a favorable influence on the pain which is characteristic of this disease. For 2 patients with myeloma