A primary objective of symptom control and supportive care in clinical trials is to improve health-related quality of life. However, in the past, most such clinical trials have concentrated on limited outcomes, such as control of anorexia or pain, and have not taken into account the broader outcome of health-related quality of life. The multidimensional tools needed to carry out these trials are now available, and several studies have yielded results that are informative and useful. These include studies on ameliorating anorexia and weight loss, fatigue and anemia, postchemotherapy nausea and vomiting, and pain from bone metastases. Examples of such studies are given. However, there is still much to learn, and investigators are urged to continue to measure health-related quality of life in clinical trials of symptom control and supportive care.