Background: During their hospitalization, children and adolescents with cancer experience a reduction in their physical, emotional and social functioning because of the aggressive treatment regime, which may result in lowered quality of life. Aim: Review of the quality of life of children and adolescents with any form of cancer in the treatment phase. Method: A search in was conducted in the electronic databases PubΜed, Cinahl, Αmerican Cancer Society, Association of Pediatric Hematology Oncology Nurses and Wiley Online Library, using the key-words: “Children”, “adolescents”, “cancer”, “quality of life”, and critical analysis was made of the important articles on the subject. From the search, 45 articles were found of relevance to this issue, of which only 29 included comprehensive information. Results: Children and adolescents with any form of cancer experience decreased quality of life in the first months following diagnosis, because of the effects of treatment and the presence of complications. Significant improvement is observed on evaluation of their quality of life after the first year from the diagnosis. Differences are observed in their physical, emotional and social state, depending on age, sex, the diagnosis and the treatment. Conclusions: The aim of interdisciplinary care team should be the continuous assessment of children and adolescents with cancer, to evaluate their quality of life with precision in the treatment phase.