Introduction: Gastro-oesophageal reflux disease (GORD) is common among chronic obstructive pulmonary disease (COPD) patients and may have a deleterious effect on COPD prognosis. However, few studies have investigated whether GORD increases the risk of severe outcomes such as intensive care unit (ICU) admittance or mechanical ventilator use among COPD patients. Methods: Propensity score matching by age, sex, comorbidities and COPD severity was used to match the 1,210 COPD patients with GORD sourced in this study to 2,420 COPD patients without GORD. The Kaplan-Meier method was used to explore the incidence of ICU admittance and machine ventilation with the log rank test being used to test for differences. Cox regression analysis was used to explore the risk of ICU admittance and mechanical ventilation use for patients with and without GORD. Results: During the 12-month follow-up, GORD patients and non-GORD patients had 5.22 and 3.01 ICU admittances per 1000 person-months, and 4.34 and 2.41 mechanical ventilation uses per 1000 person-month, respectively. The log rank test revealed a difference in the incidence of ICU admittance and machine ventilation between the two cohorts. GORD was found to be an independent predicator of ICU admittance (adjusted hazard ratio (HRadj) 1.75, 95% confidence interval (CI) 1.28-2.38) and mechanical ventilation (HRadj 1.92, 95% CI 1.35-2.72). Conclusion: This is the first investigation to detect a significantly higher incidence rate and independently increased risk of admission to an ICU and mechanical ventilation use among COPD patients who subsequently developed GORD during the first year following their GORD diagnosis than COPD patients who did not develop GORD.