The COVID-19 coronavirus pandemic is affecting the somatic and mental health of populations across the planet. Patients with cancer form a risk group with severe complications of COVID-19. The objective of the study was to examine the quality of life of children and adolescents after completion of antitumor therapy in a pandemic setting. Materials and methods. Specialists from of the clinical and rehabilitation scientific center “Russkoye pole” of the Dmitri Rogachev National Medical Research Center for Pediatric Hematology, Oncology and Immunology conducted a comparative analysis of the results of testing patients and their parents according to the PedsQL™4.0 questionnaires. Results. Patients hospitalized in 2021 have lower physical functioning parameters (63.62) than patients hospitalized before the pandemic in the first half of 2019 (70.89), p < 0.001. Parents reported significantly more positive attitudes towards quality of life assessments during the pandemic compared to those made by children. Conclusion. Differences in quality of life scores between patients in remission of oncohematological diseases before the pandemic and in the pandemic setting based on both children's and parents' assessments have been identified, which may be due to the impact of the novel coronavirus pandemic on some aspects of child and adolescent functioning. Key words: quality of life, oncohematological diseases, COVID-19 coronavirus pandemic, children