Purpose: There are few randomised controlled trials (RCTs) in paediatric surgery, and their risk of bias is unknown. Little is known about the methodological or reporting quality of systematic reviews and meta-analyses in paediatric surgery. Therefore, we conducted a cross-sectional study to determine the risk of bias and reporting quality of RCTs, systematic reviews and meta-analyses in paediatric surgery, and the associations between these outcomes and study characteristics. Methodology: We searched MEDLINE, Embase, Cochrane Library, JBI EBP Database, Centre for Reviews and Dissemination and Web of Science and 2021 indexes of high-impact paediatric surgery journals for all RCTs and systematic reviews in paediatric surgery published in 2021. We assessed the risk of bias and reporting quality of RCTs using the RoB 2 and CONSORT tools respectively, and repeated this process for systematic reviews and meta-analyses using the ROBIS and PRISMA tools. Results: We found 82 RCTs and 289 systematic reviews/meta-analyses published in 2021. More than half of RCTs (56%) and almost all systematic reviews/meta-analyses (96%) were at high risk of bias. Only 1% of RCTs and 1% of systematic reviews/meta-analyses were adequately reported. Less than half of RCTs (49%) and systematic reviews/meta-analyses (27%) had a registered protocol. Surprisingly, 56.1% of systematic reviews/meta-analyses had no risk of bias assessment. Conclusions: Recent paediatric surgery RCTs and systematic reviews show high bias and poor reporting quality. Journals, universities, and research institutions should enhance author training to improve reporting quality and reduce bias. However, biased research may still have clinical value.