In a recent report the historical aspects of the use of β-chloroethyl amines (halogenated alkyl amines, nitrogen mustards) in the treatment of certain diseases of the blood-forming organs were presented and the chemical, pharmacologic, toxicologic and animal experimental aspects of these compounds reviewed.1The interested reader is referred to that report for orientation. The present preliminary communication concerns the clinical use of halogenated alkyl amines in the treatment of lymphosarcoma, Hodgkin's disease, leukemia and a limited number of allied and miscellaneous disorders. In all, 67 patients have been studied. These include 7 patients2treated by L. S. Goodman and Alfred Gilman at the New Haven Hospital; 34 patients treated by M. M. Wintrobe and Margaret T. McLennan at the Salt Lake County General Hospital; 16 patients treated by William Dameshek, Boston, and 10 patients treated by M. J. Goodman, Portland, Ore. The types of diseases treated are shown