PURPOSE: Clinicians often make decisions for their patients, despite evidence that suggests that correspondence between patient and clinician decision making is poor. The management of colorectal cancer presents difficult decisions because the impact of treatment on quality of life might overshadow its survival efficacy. This study investigated whether patients are able to trade survival for quality of life as a means to express their preference for treatment options and to compare their preferences with those expressed by clinicians. METHODS: Patients undergoing curative surgery for colorectal cancer were interviewed post-operatively to elicit their preferences in four hypothetical treatment scenarios. A questionnaire was mailed to all Australian colorectal surgeons and medical oncologists that asked them to respond as if they themselves were patients. RESULTS: One hundred patients (91 percent), 43 colorectal surgeons (77 percent), and 103 medical oncologists (50 percent) participated. In all four scenarios, patients were able to trade survival for quality of life. Patients' responses varied between scenarios, both in willingness to trade and the average amount traded. There were significant differences between patients and clinicians. Clinicians were more willing than patients to trade survival to avoid a permanent colostomy in favor of chemoradiotherapy. Patients' strongest preference was to avoid chemotherapy, more than to avoid a permanent colostomy. CONCLUSIONS: Patients are able to trade survival as a measure of preference for quality of life and can do so differentially between treatment scenarios. Patients' preferences do not always accord with those of clinicians. Unless patients' preferences are explicitly sought and incorporated into clinical decision making, patients may not receive the treatment that is best for them.