As cancer gains on heart disease as the leading cause of death, there is increased urgency to improve the current diet that contributes to 35 percent of cancer deaths. Lacking have been consensus about the strength of the science base, political will, resources, and conceptualization about what can be done in communities to change dietary behaviors. Over the past 10 years, the 5 A Day for Better Health Program has emerged as the major population-based initiative for nutrition and cancer prevention. The 5 A Day Program is a national theory-based program that approaches Americans with a simple, positive message: eat five or more servings of fruit and vegetables daily as part of a low-fat, high-fiber diet. This article describes the elements and theories woven into the national 5 A Day Program, provides a description of the important components of the program, and outlines the issues that will face dietary change initiatives in the future.