Delayed graft function (DGF) continues to represent one of the most frequently encountered early complications following kidney transplantation. Despite notable progress in donor and recipient pretreatment protocols, diagnostic techniques and therapeutic approaches, the incidence of DGF, along with its associated short- and long-term sequelae, has not demonstrated a significant reduction. DGF is influenced by a multitude of factors, and individuals with exposure to these risk factors exhibit a markedly increased probability of developing DGF.To systematically identify and evaluate risk factors associated with DGF in kidney transplant recipients.A systematic review and meta-analysis DATA SOURCES: A comprehensive search was performed across multiple databases, including PubMed, Embase, The Cochrane Library, Web of Science, CNKI, Wanfang, VIP and SinoMed, from the inception of each database until 1 March 2024.OR and OR 95% CI of risk factors for DGF.The meta-analysis included 19 studies involving a total of 153 008 patients, of whom 96 596 (63.1%) developed DGF. The following risk factors for DGF were identified: prolonged cold ischaemia time (CIT) (OR=1.05, 95% CI=1.03 to 1.07, p<0.0001), elevated donor end-stage serum creatinine (OR=1.54, 95% CI=1.26 to 1.87, p<0.0001), extended dialysis vintage (OR=1.02, 95% CI=1.00 to 1.02, p=0.014), increased human leucocyte antigen (HLA) mismatch number (OR=1.19, 95% CI=1.06 to 1.33, p=0.004), higher donor body mass index (BMI) (OR=1.07, 95% CI=1.03 to 1.11, p<0.0001), advanced donor age (OR=1.02, 95% CI=1.01 to 1.03, p=0.003) and recipient diabetes mellitus (OR=1.52, 95% CI=1.40 to 1.64, p<0.0001).This meta-analysis identified seven significant risk factors for DGF, including prolonged CIT, elevated donor end-stage serum creatinine, extended dialysis vintage, increased HLA mismatch number, higher donor BMI, advanced donor age and recipient diabetes mellitus. These findings may offer potential insights for developing clinical strategies to mitigate the risk of DGF in kidney transplant recipients and improve postoperative management.CRD42024520542.© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.