Flexibility is a health-related physical fitness component that has its importance related to the maintenance of functional independence and achievement of activities of the daily living. This systematic review aims to analyze the existing evidence in the literature regarding physical capacity flexibility in Brazilian children and adolescents. Searches were conducted in the Virtual Health Library, Scientific Electronic Library Online, Sportdiscus databases through the EBSCOhost and Pubmed platform. There were 89,553 articles, of which 69,197 were excluded for duplicity, 20,124 for the title, 160 for the abstract, 56 after a full analysis of the article, remaining 16 articles for the qualitative analysis. Of these, from the reading of references, 57 titles partially eligible for the review were identified, and after the application of the eligibility criteria, there were only 18 for the qualitative analysis. Of the 34 studies included for the qualitative analysis, 25 studies were excluded and nine were included in the review. All articles presented the cross-sectional design and used the sit-and-reach test to assess flexibility. It was evidenced that: a) flexibility has been treated as co-adjuvant in studies with children and adolescents; b) although females have absolute flexibility values greater than the opposite sex, males have higher frequency of subjects that meet the health classification criteria in this variable; c) there is greater prevalence of the use of FITNESSGRAM and PROESP-BR reference standards.