Aims Ivabradine and sacubitril/valsartan are second-line therapies for patients with heart failure and reduced ejection fraction (HFrEF) based on guideline recommendations. We aimed to evaluate the synergistic effects of these two medications. Methods and results Patients' data were extracted from a multicentre database between 2016 and 2018. Patients were classified into (1) Simultaneous group: simultaneous prescription of ivabradine and sacubitril/valsartan within 6 weeks; (2A) Sequential group, ivabradine-first: ivabradine was prescribed first, followed by sacubitril/valsartan; and (2B) Sequential group, sacubitril/valsartan-first: sacubitril/valsartan was prescribed first, followed by ivabradine. A total of 464 patients with HFrEF were enrolled. Cardiovascular death and/or unplanned re-hospitalizations for HF were less frequent (28.6% vs. 44.8%, P = 0.01), and the improvement of left ventricular ejection fraction (LVEF) was significantly greater in patients from the Simultaneous group than those from the Sequential group (ΔLVEF 12.8 ± 12.9% vs. 9.3 ± 12.6%, P = 0.007). Among Sequential subgroups, the ivabradine-first treatment decreased heart rate and increased systolic blood pressure (SBP) compared with sacubitril/valsartan-first treatment (Δheart rate À9.1 ± 12.9 b.p.m. vs. 2.6 ± 16.0 b.p.m., P < 0.001; ΔSBP 4.6 ± 16.5 mmHg vs. À4.8 ± 17.2 mmHg, P < 0.001), whereas sacubitril/valsartan-first treatment showed a higher degree of LVEF improvement (ΔLVEF 3.6 ± 7.8% vs. 0.7 ± 7.7%, P = 0.002) than ivabradine-first treatment. At the end of follow-up, SBP, LVEF, and left ventricular volume were comparable between two Sequential subgroups. Conclusions Among patients with HFrEF, simultaneous rather than sequential treatment with sacubitril/valsartan and ivabradine was a better strategy to reduce adverse events and achieve left ventricular reverse remodelling. Ivabradine treatment had a more significant benefit on improving haemodynamic stability, whereas sacubitril/valsartan treatment showed a more significant effect on improving LVEF.