Fatigue in children and adolescents with cancer undergoing treatment is a subjective and multifactorial symptom, which is related to the effects of the disease and treatment as well as to other biological, physiological, social and psychological factors. Fatigue is estimated to range from 25-99% during cancer treatment.The aim of the study was to explore cancer related fatigue (CRF) in children and adolescents during the treatment phase.Methodology: Review of the literature conducted by searching for articles in international bibliographic databases (Medline, Scopus, Embase & Cochrane Library, Google Scholar) from 1998-2021.Results: Children and adolescents with cancer identify fatigue as one of the most common and stressful symptoms they experience from diagnosis and treatment until long-term follow-up. The experience of fatigue in children and adolescents is subjective and experienced differently depending on their developmental level. The main factors that affect the intensity of fatigue are chemotherapy, radiotherapy, medication, sleep disorders, anorexia, poor quality of life, emotional distress, reduced physical activity and accompanying health problems. Fatigue has a negative impact on the daily functioning and mental state of children and adolescents. Assessment of cancer-related fatigue involves four phases: diagnosis, assessment, intervention, and reassessment. Information about the symptom of fatigue due to the underlying disease or treatment and the importance of reporting this symptom should be given at the start of treatment.Conclusions: Nurses should systematically evaluate fatigue in children and adolescents with cancer receiving treatment and inform them to report it as a symptom.