BackgroundChildren undergoing surgery and their parents are at risk of developing post-traumatic stress reactions. We systematically reviewed the literature to understand the prevalence of this issue, as well as potential risk factors.MethodsWe conducted a systematic review and meta-analysis, using PubMed, PsycInfo, Web of Science and Google Scholar, with searches conducted in February 2021. Papers were included if they measured post-traumatic stress in children and/or parents following paediatric surgery and were excluded if they did not use a validated measure of post-traumatic stress. Data were extracted from published reports.FindingsOur search yielded a total of 1672 papers, of which 16 met our inclusion criteria. In meta-analysis, pooled studies of children estimated an overall prevalence of 16% meeting criteria for post-traumatic stress disorder post surgery (N=187, 95% CI 5% to 31%, I²=80%). After pooling studies of parents, overall prevalence was estimated at 23% (N=1444, 95% CI 16% to 31%, I²=91%). Prevalence rates were higher than those reported in the general population. Risk factors reported within studies included length of stay, level of social support and parental mental health.InterpretationThere is consistent evidence of traumatic stress following surgery in childhood which warrants further investigation. Those delivering surgical care to children would benefit from a raised awareness of the potential for post-traumatic stress in their patients and their families, including offering screening and support.