Patients with metastatic breast and prostate cancer are not curable. The aim of treatment is palliation, i.e., optimizing quality of life. Unfortunately, this end point has not often been measured. Two recent trials have examined the relationship between intensity of chemotherapy and therapeutic benefit for metastatic breast cancer. Quality of Life as assessed by linear analog self-assessment (LASA) scales was included as a primary endpoint. The trials suggested improved quality of life for standard dose, continuous chemotherapy as compared to reduced dose or intermittent treatment. These results are important in establishing the palliative value of chemotherapy for treatment of metastatic breast cancer. In addition, a series of LASA scales has been developed for assessing quality of life in prostate cancer. Assessment of quality of life should be incorporated in trials of therapy for metastatic breast and prostate cancer.