Background and aimsClinical comparisons of angiotensin receptor–neprilysin inhibitors (ARNI) and sodium–glucose cotransporter 2 inhibitors (SGLT2i) treatment in patients with HFrEF and T2DM are limited. This study evaluated the clinical outcomes and treatment benefits of SGLT2i versus ARNI treatment in patients with HFrEF and T2DM in a large real-world data set.MethodsWe identified 1487 patients with HFrEF and T2DM who were undergoing ARNI or SGLT2i treatment for the first time (n= 647 and 840, respectively) between January 1, 2016, and December 31, 2021, and with clinical outcomes of CV death, hospitalization for heart failure (HHF), composite CV outcomes, or renal outcomes.ResultsThe HHF risk reduction conferred by SGLT2i treatment was more significant than that conferred by ARNI treatment (37.7% vs. 30.4%; 95% confidence interval [CI] 1.06–1.41). SGLT2i use conferred significantly greater renal protection against the doubling of serum creatinine (13.1% vs. 9.3%; 95% CI 1.05–1.75), an estimated glomerular filtration rate decline of > 50% (24.9% vs. 20.0%; 95% CI 1.02–1.45), and progression to end-stage renal disease (3.1% vs. 1.5%; 95% CI 1.62–5.23). The improvements in echocardiographic parameters were comparable between the groups.ConclusionsCompared with ARNI treatment, SGLT2i treatment was associated with a more significant HHF risk reduction and greater preservation of renal function in patients with HFrEF and T2DM. This study also supports the prioritization of SGLT2i use in these patients when patients' conditions or economic resources need to be considered.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13098-023-01081-2.