The aim of this study was to evaluate the safety profile in terms of changes in renal function after co-treatment with sacubitril/valsartan and empagliflozin in patients with type 2 diabetes (T2D) and heart failure with reduced ejection fraction (HFrEF). This multicentre observational analysis included 108 patients with T2D and HFrEF treated with both agents: baseline sacubitril/valsartan (Group A; n = 43), baseline empagliflozin (Group B; n = 42), or both agents initiated simultaneously (Group C; n = 23). The primary endpoint was estimated glomerular filtration rate (eGFR) dynamics across treatment groups. A binary characterization of worsening renal function (WRF)/improved renal function (IRF) was included in the primary endpoint. WRF and IRF were defined as an increase/decrease in serum creatinine ≥ 0.3 mg/dL or GFR ≥ 20%. Changes in quantitative variables were evaluated using joint modelling of survival and longitudinal data (JM). Rates and their treatment differences were determined by Poisson regression. The mean left ventricle ejection fraction and eGFR were 32 ± 6% and 70 ± 28 mL/min/1.73 m 2, respectively. At a median follow-up of 1.01 years (inter-quartile range 0.71-1.50), 377 outpatient visits were recorded. Although there were differences in GFR trajectories over time within each treatment, they did not achieve statistical significance (omnibus P = 0.154). However, when these differences were contrasted among groups, there was a significant decrease in GFR in Group A as compared with Group B (P = 0.002). The contrast between Groups C and B was not significant (P = 0.430). These differences were also reflected when the rates for WRF and IRF were contrasted among treatments. The co-administration of sacubitril/valsartan and empagliflozin in patients with HFrEF and concomitant T2D appears to be safe in terms of renal function.