Symptom distress in the adult population with cancer is of concern to clinicians who care for these patients. Increased research has been directed toward the development and refinement of symptom distress scales, the identification of determinants of symptom distress, the investigation of symptom distress as a predictor, and the examination of the relationship between quality of life and symptom distress. Findings from this research have increased our understanding of symptom distress in adult patients with cancer. However, a major limitation of work to date has been a lack of consensus related to the definition and measurement of the symptom distress construct. The purpose of this article is to address existing conceptual and methodological challenges inherent in the study of symptom distress, and to make recommendations for further research in this area.