Heart failure is a major health problem in the United States leading to high rates of mortality and morbidity and impaired quality of life. Assisting patients to improve compliance with their self-care regimen, including medications, dietary sodium restrictions, and self-monitoring (daily weights, edema assessment), may improve these poor outcomes. This article describes the development and initial evaluation of Heart Messages, a theory-based, tailored message intervention to improve compliance with the self-care regimen recommended for patients with heart failure. The project involved four phases, each of which is described in this article. The Heart Messages tailored message intervention program is available in both printed and Web-based formats. In a pilot study and clinical evaluation project, the program was found to be useful for patient education and feasible for implementation. Larger randomized trials are now warranted to evaluate the effectiveness of the intervention in improving compliance with the self-care regimen and thereby improving outcomes among patients with heart failure.