OBJECTIVE: Fatigue is having high prevalence and increased acknowledgment of negative effect on the patient's well-being which has resulted in fatigue being important research variable in breast cancer patients. The recent development shows greater receptivity of health professionals to assessing cancer-related fatigue (CRF). In this review, an attempt has been made to identify CRF instruments which have been used in breast cancer patients with the detailed description about the instruments and their psychometric properties. METHOD: A search was conducted from January 2000 to April 2020 from electronic databases such as PubMed, Cochrane, Embase, and Google Scholar. The studies were included if the instrument was used to measure fatigue in breast cancer patients and its description and psychometric properties reported in breast cancer patients. The search was limited to studies in the English language and use of English version of instruments. RESULTS: Among 34 CRF instruments, 9 instruments were included according to inclusion and exclusion criteria. From nine instruments, six were multidimensional, two were unidimensional, and one instrument was quality-of-life (QOL) subscale. All the scales have showed accepted reliability and validity in breast cancer patients. A minimal clinically important difference was available for Multidimensional Fatigue Symptom Inventory - Short Form, Brief Fatigue Inventory, Piper Fatigue Scale - Revised, FACIT Fatigue scale, and Fatigue symptom inventory instruments. SIGNIFICANCE OF RESULTS: This review will help healthcare providers who are dealing with breast cancer patients to acknowledge and better understand what their patients are experiencing. The most appropriate tool will allow healthcare providers to use for holistic assessment of CRF. The instrument will help them to monitor their patient's condition or treatment progress, so it can be incorporated into treatment decisions for better management of fatigue.