The question of the choice of treatment for sarcoma of the soft parts is constantly recurring, with proponents of radical or conservative surgical intervention and of irradiation. In an effort to answer this question in part, the study reported on here was undertaken. Among the reports of fibrosarcoma of the soft parts in the files of the pathologic laboratories of the Huntington Memorial Hospital and the Palmer Memorial Unit of the New England Deaconess Hospital, records of one hundred and sixty-three cases were found with adequate clinical data for careful study. In many other cases sarcoma had been diagnosed, but either the follow up or the history was unsatisfactory.. The follow-up period for the living patients ranges from thirty-one years in one case to ten months for a patient operated on in 1934 and included because of the interest of the case. The great majority of patients have been followed