Background: Quality-of-life considerations are important in metastatic prostate cancer. In this study, we interviewed physicians and patients about their assessments and expectations on quality of life as metastatic prostate cancer progresses. Methods: Physicians and patients made utility assessments of three hypothetical health states for metastatic disease using the time trade-off technique. Scores were bounded on a scale from 0.0 (death) to 1.0 (perfect health). Results: Patients rated each of the health states as less desirable than the physicians. Conclusions: Physicians and patients differ in their perspectives on expected quality of life with metastatic prostate cancer. Our results emphasize the need to assess patients' utilities directly.