Background and aims: the DUAL I-V clinical trials investigated the efficacy and safety of IDegLira versus different comparators; basal insulin, glucagon-like peptide-1 receptor agonist (GLP-1 RA) and placebo. This post hoc analysis aimed to evaluate the effects of IDegLira versus comparators in patients with type 2 diabetes (T2D) as a function of baseline renal function. Materials and Methods: patients were grouped by their baseline renal function (normal, mild or moderate impairment, with estimated glomerular filtration rates [eGFR] of >=90, >=60-<90 and >=30-<60 mL/min/1.73 m2, respectively). Results: HbA1c reductions from baseline to end of trial were significantly greater with IDegLira versus comparators in all baseline renal function groups. Across renal function groups, hypoglycaemia rates were lower with IDegLira versus basal insulin but higher versus GLP-1 RA and placebo, and eGFR was unchanged at the end of trial for all treatments. Adverse event rates (per patient-year of exposure) were similar for patients with normal, mild and moderate renal impairment, respectively (IDegLira [4.1, 3.8 and 4.6]; basal insulin [3.6, 3.6 and 3.5]; GLP-1 RA [4.8, 4.9 and 4.5]; placebo [3.0, 4.1 and 4.6]). Conclusion: in conclusion, IDegLira is safe and more efficacious than comparators in patients with T2D with mild or moderate renal impairment with lower hypoglycaemia rates when compared with basal insulin. The results resemble those observed in patients with normal renal function.