Abstract Background Heart failure with reduced ejection fraction (HFrEF) can coexist with chronic obstructive pulmonary disease (COPD), which complicates the clinical situation and worsens quality of life. The study used standard diagnostic criteria for detecting COPD in hospitalized HFrEF patients and to survey the influence of other comorbidities and medications on the long-term outcomes of HFrEF + COPD patients. Methods We retrospectively recruited patients hospitalized due to HFrEF in a tertiary medical center and examined and followed up clinical outcomes, including length of hospital stay, mortality, and readmission episodes, for a 5-year period. Risk factors for mortality were analyzed using multivariate analysis. Results Of the 118 hospitalized HFrEF study participants, 68 had concurrent COPD whereas 50 did not. There was a significant increase in the male predominance, smoking history, higher hemoglobin level and increased length of hospital stay in the HF + COPD group than in the HF-only group. Lower left ventricular ejection fraction was found in the HF and COPD comorbidity group. In multivariate analysis, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) use independently associated with a beneficial effect on survival in HF patients with COPD. Oral corticosteroid uses and stroke as a comorbidity were independently associated with a shorter time to the first readmission episode. Conclusion In HFrEF patients, COPD was associated with a prolonged length of hospital stay. ACEI/ARB use might relate to a beneficial effect on survival in HF patients with COPD. The use of maintenance oral corticosteroid in patients with both HF and COPD should be crucially evaluated to determine the clinical benefit and disadvantages.