This article describes an intervention strategy designed to provide decisional support for patients with cancer who want to participate in medical-treatment decisions. This strategy is based on the concepts of commitment and control and on a simple technique for determining the degree of involvement the patient desires. It has been tested on women with a confirmed diagnosis of breast or gynecologic cancer and on women referred for a second opinion and diagnostic workup for suspicious lesions. The emphasis is on the patient's agenda, including assessing to what extent she wants to participate, helping her to identify questions, and supporting her in obtaining the information she wants and needs. The strategy has been incorporated successfully into a busy oncology clinic schedule. The next challenge is to conduct research to evaluate the effect of providing decisional support on quality of life.