AIMTo understand the influence of chronic kidney disease (CKD) on mortality, need for transfusion and rebleeding in gastrointestinal (GI) bleeding patients.METHODSA systematic search was conducted in three databases for studies on GI bleeding patients with CKD or end-stage renal disease (ESRD) with data on outcomes of mortality, transfusion requirement, rebleeding rate and length of hospitalization (LOH). Calculations were performed with Comprehensive Meta-Analysis software using the random effects model. Heterogeneity was tested by using Cochrane’s Q and I2 statistics. Mean difference (MD) and OR (odds ratio) were calculated.RESULTS1063 articles (EMBASE: 589; PubMed: 459; Cochrane: 15) were found in total. 5 retrospective articles and 1 prospective study were available for analysis. These 6 articles contained data on 406035 patients, of whom 51315 had impaired renal function. The analysis showed a higher mortality in the CKD group (OR = 1.786, 95%CI: 1.689-1.888, P < 0.001) and the ESRD group (OR = 2.530, 95%CI: 1.386-4.616, P = 0.002), and a rebleeding rate (OR = 2.510, 95%CI: 1.521-4.144, P < 0.001) in patients with impaired renal function. CKD patients required more unit red blood cell transfusion (MD = 1.863, 95%CI: 0.812-2.915, P < 0.001) and spent more time in hospital (MD = 13.245, 95%CI: 6.886-19.623, P < 0.001) than the controls.CONCLUSIONESRD increases mortality, need for transfusion, rebleeding rate and LOH among GI bleeding patients. Prospective patient registries and observational clinical trials are crucially needed.