Decision making is fundamental to all aspects of cancer care--prevention, detection, treatment, survivorship, and end of life--yet researchers and clinicians have limited knowledge of the ways in which patients and their health care providers make critical health decisions. Recognizing how important it is to understand how patients and their providers make potentially life-altering decisions, the National Cancer Institute developed a decision making in cancer control initiative. The goal of this initiative is to enhance understanding of human decision-making processes so that individuals can make more informed and satisfying choices regarding their health. This article describes the multidisciplinary meeting that provided the scientific foundation for this initiative.