As the result of a major prevention and control effort, public health measures directed toward reducing smoking are slowly succeeding (1). Of parallel importance, and the focus of this article, is the research evidence that indicates direct and significant correlations between cancer and certain food groups such as vegetables, fruits, and fiber; the specific components in these foods that may influence cancer risk at several sites; and the intervention trials supported by the National Cancer Institute as part of its chemoprevention research program. The latter includes studies of nutrients and other food constituents as well as pharmaceutical agents that may be useful for cancer prevention.