From 1945 to 1959, thirty-four patients with malignant tumor of the extremities were treated by exarticulation at the University of Michigan Medical Center. Two of these patients were so treated to palliate painful metastatic lesions. In three others, all of whom were treated by hemipelvectomy, incomplete removal of the tumor at the time of surgery was recognized. Of the thirty-two patients treated for primary malignant tumors in the extremities, fourteen are still alive. Of ten patients who had disarticulation of the hip, only one has survived longer than five years; another still survives, at the time of writing, two and one-half years after operation. Of the sixteen patients undergoing hemipelvectomy, four have survived more than five years; three more, who were operated on less than five years ago, are alive at the time of writing. Of eight patients who had forequarter amputation, three have survived longer than five years, and three more are still alive less than five years after operation.