OBJECTIVES: To identify and describe currently available instruments to measure patient-reported outcomes and perceptions of cancer-related fatigue. METHODS: A literature review was performed in several electronic sources including the U.S. National Cancer Institute website and the Medline database (1966-2004) using the keywords: fatigue, asthenia, questionnaire, scale, instrument, oncology, cancer, assessment, measure, measurement, expectation/s, relief, satisfaction, perception/s, worry/ies. Articles located were hand-searched for further relevant articles. A citation was selected for review when it referred to the use or development of patient reported instrument(s) to measure the impact of cancer-related fatigue or its treatment and/or patients expectations, beliefs and concerns regarding cancer-related fatigue. For each questionnaire located the following data was reviewed: instruments’ name, target population, item number, dimensions, response scale and time frame. RESULTS: In total, 35 citations were selected and reviewed, which referred to 30 different instruments (27 patient-reported outcome questionnaires –PRO's– and 3 epidemiological survey instruments) used to measure several aspects of cancer-related fatigue. Questionnaires ranged from a single item to 40 items, and the number of dimensions from 1 to 7. Almost all of the PRO's focused on aspects such as the intensity, frequency and duration of fatigue, though some also measured one or more of the following: quality of life, distress, psychological impact and impact on motivation/activity, and barriers to patient-physician communication. The survey instruments located were more likely to focus on patient’s attitudes and beliefs regarding physician-patient interaction, psychosocial issues, accessing information, satisfaction with fatigue management and perceptions of causes, among others. CONCLUSIONS: Though there appears to be a surfeit of instruments to measure the intensity, frequency and duration of cancer-related fatigue, and some emphasis on the way fatigue affects quality of life there are few instruments which incorporate other aspects such as beliefs, expectations and attitudes which may also be useful in clinical practice.