The primary objective of the study was to assess the prevalence of burnout among paediatric residents during the coronavirus disease 2019 (COVID-19) outbreak in France. The secondary objective was to identify risk factors associated with burnout in this population. In a nationwide, cross-sectional survey, a questionnaire was e-mailed to all paediatric residents in France in the first week of May 2020. The prevalence of burnout was assessed with the validated French-language version of the Maslach Burnout Inventory – Human Services Survey. The questionnaire also contained items on the residents’ sociodemographic characteristics and professional situation. Three hundred and forty paediatric residents completed the questionnaire. The median age was 27 (interquartile range 25–28) and 285 (83.8%, 95% confidence interval (CI) [79.5–87.6]) of the residents were women. The prevalence of burnout was 37.4%, 95%CI [32.2–42.7]. There was no association between burnout and exposure to the consequences of COVID-19, which may be related to the low incidence of severe COVID-19 among children. In contrast, the hours worked per week and the anxiety scores were significantly associated with burnout. Conclusion : The level of burnout among French paediatric residents is a matter of concern for residents, and cannot be ascribed to the COVID-19 outbreak. Preventive actions should be implemented, with a reduction in working hours and support programs to help manage work-related anxiety. What is Known: • Burnout is a concern for both residents and the patients they care for. • Natural disasters disrupt the health care organizations and increase the burnout rate. What is New: • The prevalence of burnout among paediatric residents in France is 37.4%, 95%CI [32.2–42.7]. • COVID-19 outbreak is not associated with burnout in this population but anxiety and working hours per week might be modifiable risk factors. Supplementary Information The online version contains supplementary material available at 10.1007/s00431-020-03907-x.