The appropriate technology for control of diseases of economically underdeveloped countries happens to be mainly that applicable to groups as a whole; whereas that effective for most diseases of industrialized societies must be individually delivered. The latter area is where the pharmaceutical industry has scored its greatest triumphs, yet most of this technology does not fit the major disease problems as they now exist in the developing countries. The argument is presented that in order for the U.S. industry to do more in the developing countries, the most needed invention is not a new drug, but a new system for drug development—a new R & D system tailored specially to both the financial and the biologic needs of the problem.