Patients with metastatic cancer are often offered systemic chemotherapy, although it is not usually curative in this situation. The impact of treatment on survival may be small and the intention is mainly to palliate symptoms and to improve the patient's quality of life. Traditional end points in clinical trials tend to focus on cancer outcomes, such as tumour shrinkage or survival. Trials of palliative chemotherapy should focus on patient outcomes that reflect the aims of treatment. There are now a large number of instruments available to measure quality of life and the difficulty lies in deciding which tools are appropriate and applying them consistently to give results that are robust enough to enable clinical decision making. This is particularly challenging in a population of patients with a high degree of morbidity. In addition, economic end points are becoming increasingly relevant in the current climate: as newer treatments become available, the ways in which costs may be balanced against the potential benefits in terms of gains in quality of life become important.