PurposeWe assessed cardiorespiratory fitness and health-related quality of life (HRQoL) in survivors of childhood central nervous system (CNS) tumours.MethodsParticipants were recruited from the National Children’s Cancer Service in Children’s Health Ireland at Crumlin. Inclusion criteria included diagnosis of a primary CNS tumour, aged between 6 and 17 years, between 3 months and 5 years post completion of oncology treatment, independently mobile, and deemed clinically appropriate to participate by treating oncologist. Cardiorespiratory fitness was assessed using the six-minute walk test. HRQoL was assessed with the PedsQL Generic Core Scales, Version 4.0.ResultsThirty-four participants (n= 16 male) were recruited, with a mean age of 12.21 ± 3.31 years and a mean time since completion of oncology treatment of 2.19 ± 1.29 years. Mean six-minute walk distance (6MWD) achieved was 489.56 ± 61.48 m, equating to the 8thpercentile overall. 6MWD was significantly reduced when compared to predicted population norms (p< 0.001). PedsQL parent proxy-report and child-report scores were significantly lower when compared to healthy paediatric norms (p< 0.001 –p= 0.011). A significant positive correlation was found between 6MWD and both parent proxy-report (r = 0.55,p< 0.001) and child-report (r = 0.48,p= 0.005) PedsQL total scores.ConclusionSurvivors of childhood CNS tumours present with impaired cardiorespiratory fitness and HRQoL. Higher levels of cardiorespiratory fitness are associated with higher levels of HRQoL.Implications for Cancer SurvivorsRoutine screening of cardiorespiratory fitness and HRQoL in survivors of childhood CNS tumours may be beneficial. Healthcare providers should encourage and provide education on the potential benefits of physical activity to improve overall quality of life.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00520-023-07854-9.