The National Institutes of Health is the largest biomedical research institution in the world. It has become one of the world's most highly respected research centers in part because of its efforts over the years to provide the research community with leadership in both the ethical and scientific parameters of research involving humans. As its 113th birthday approaches at the turn of the century, its great legacy is providing an environment to stimulate and nourish the diversity and creativity of ideas, and thereby enable science to progress. This research must continue to be guided and tempered by consistent and critical federally-supported ethical analyses.