Background: In patients with heart failure (HF) and reduced ejection fraction (HFrEF) with or without type 2 diabetes mellitus, the sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin was recently shown to reduce the risk of worsening HF or death from cardiovascular causes in the dapagliflozin in patients with heart failure and reduced ejection fraction (DAPA-HF) trial. Our goal was to investigate how many patients in a real-world setting would be eligible for dapagliflozin according to the DAPA-HF enrolment criteria. Methods: This is a single-center retrospective study enrolling consecutive, unselected patients followed up in an HF clinic from 2013 to 2019. Key DAPA-HF inclusion criteria (i.e., left ventricular ejection fraction [LVEF] ≤40% and NT-proBNP ≥600 pg/mL [or ≥900 pg/mL if atrial fibrillation]) and exclusion criteria (estimated glomerular filtration rate [eGFR] <30 mL/kg/1.73 m2 and systolic blood pressure [SBP] <95 mm Hg) were considered. Results: Overall, 479 patients (age 76 ± 13 years; 50.5% male; 78.9% hypertensive; 45.1% with an eGFR <60 mL/min/1.73 m2; 36.5% with TD2M; and 33.5% with ischaemic HF) were assessed. The median SBP was 128.5 (112.0-146.0) mm Hg, mean eGFR was 50.8 ± 23.7 mL/min/1.73 m2, and median NT-proBNP was 2,183 (IQR 1,010-5,310) pg/mL. Overall, 155 (32.4%) patients had LVEF ≤40%. According to the DAPA-HF trial key criteria, 90 patients (18.8%) would be eligible for dapagliflozin. The remainder would be excluded due to LVEF >40% (67.6%), eGFR <30 mL/min/1.73 m2 (19.4%), NT-proBNP below the cutoff (16.7%), and/or SBP <95 mm Hg (6.5%). If we center the analysis to those with LVEF ≤40%, 58.1% would be eligible for dapagliflozin. The remainder would be excluded due to an eGFR <30 mL/min/1.73 m2 (20%), NT-proBNP below the cutoff (16.1%), and/or SBP <95 mm Hg (8.4%). Conclusion: Roughly half of our real-world HFrEF cohort would be eligible for dapagliflozin according to the key criteria of the DAPA-HF trial. The main reason for non-eligibility was an eGFR <30 mL/min/1.73 m2. However, two-thirds of patients had LVEF >40%. These findings show that dapagliflozin is a promising complementary new drug in the therapeutic armamentarium of most patients with HFrEF, while highlighting the urgent need for disease-modifying drugs in mid-range and preserved LVEF and the need to assess the efficacy and safety of SLGT2i in advanced kidney disease patients. The results of ongoing SGLT2i trials in these LVEF subgroups are eagerly awaited.