NCCN convened a committee of experts to make recommendations for future studies of cancer-related fatigue (CRF). The committee reviewed the current data on the incidence, clinical measurement, and treatment of CRF. The assessment of fatigue is largely derived from self-report questionnaires that address the symptom of fatigue, and do not correlate the presence of fatigue with change in physical activity. The committee developed a self-report questionnaire, NCCN Fatigue and Contributing Factors Inventory, which incorporates assessments of fatigue, pain, difficulty sleeping, distress, physical activity, and concurrent medications. A clinical research study using this measure in conjunction with the NCCN Breast Cancer Outcomes Database Project is planned. The committee noted a strong interaction among fatigue, pain, difficulty sleeping, and distress and recommended that future clinical research address these interactions.