COOPERATIVE CLINICAL TRIAL RESEARCH in oncology dates back to 1955. At that time Dr. Cornelius P. Rhoads, who was the director of Sloan-Kettering Institute, proposed to the Congress that it consider supporting an effort directed toward the cooperative clinical study of better methods for the treatment of malignant diseases. This was particularly needed since in 1954 the National Cancer Institute had expanded its program to develop new drugs for the treatment of cancer. In order evaluate the clinical effectiveness of the many new agents being developed, an extensive testing facility became necessary, and the concept of cooperative clinical research groups evolved By 1958 this had burgeoned to the point that a variety of different clinical cooperative groups had been organized. Over the years older groups have been disbanded and new groups formed. Currently 17 cooperative entities exist which are supported by the National Cancer Institute and reviewed by the Cancer Clinical Investigations Review Committee.