Background and Aims Prophylactic endotracheal intubation (PEI) is often advocated to mitigate the risk of cardiopulmonary adverse events in patients presenting with brisk upper GI bleeding (UGIB). However, the benefit of such a measure remains controversial. Our study aimed to compare the incidence of cardiopulmonary unplanned events between critically ill patients with brisk UGIB who underwent endotracheal intubation versus those who did not. Methods Patients aged 18 years or older who presented at Cleveland Clinic between 2011 and 2014 with hematemesis and/or patients with melena with consequential hypovolemic shock were included. The primary outcome was a composite of several cardiopulmonary unplanned events (pneumonia, pulmonary edema, acute respiratory distress syndrome, persistent shock/hypotension after the procedure, arrhythmia, myocardial infarction, and cardiac arrest) occurring within 48 hours of the endoscopic procedure. Propensity score matching was used to match each patient 1:1 in variables that could influence the decision to intubate. These included Glasgow Blatchford Score, Charleston Comorbidity Index, and Acute Physiology and Chronic Health Evaluation scores. Results Two hundred patients were included in the final analysis. The baseline characteristics, comorbidity scores, and prognostic scores were similar between the 2 groups. The overall cardiopulmonary unplanned event rates were significantly higher in the intubated group compared with the nonintubated group (20% vs 6%, P =.008), which remained significant (P =.012) after adjusting for the presence of esophageal varices. Conclusions PEI before an EGD for brisk UGIB in critically ill patients is associated with an increased risk of unplanned cardiopulmonary events. The benefits and risks of intubation should be carefully weighed when considering airway protection before an EGD in this group of patients.