Introduction : Severe cardiovascular collapse (CVC) is a life-threatening complication after emergency endotrachealintubation (ETI) in the ICU. Many factors may interact with hemodynamic conditions during ETI, but no study todate has focused on factors associated with severe CVC occurrence. This study assessed the incidence of severeCVC after ETI in the ICU and analyzed the factors predictive of severe CVC. Methods : This was a secondary analysis of a prospective multicenter study of 1,400 consecutive intubations at 42ICUs. The incidence of severe CVC was assessed in patients who were hemodynamically stable (mean arterial bloodpressure >65 mmHg without vasoactive drugs) before intubation, and the factors predictive of severe CVC weredetermined by multivariate analysis based on patient and procedure characteristics. Results : Severe CVC occurred following 264 of 885 (29.8 %) intubation procedures. A two-step multivariate analysisshowed that independent risk factors for CVC included simple acute physiologic score II regardless of age (oddsratio (OR) 1.02,p< 0.001), age 60–75 years (OR 1.96,p< 0.002 versus <60 years) and >75 years (OR 2.81,p< 0.001versus <60 years), acute respiratory failure as a reason for intubation (OR 1.51,p= 0.04), first intubation in the ICU(OR 1.61,p= 0.02), noninvasive ventilation as a preoxygenation method (OR 1.54,p= 0.03) and inspired oxygenconcentration >70 % after intubation (OR 1.91,p= 0.001). Comatose patients who required ETI were less likely todevelop CVC during intubation (OR 0.48,p= 0.004). Conclusions : CVC is a frequent complication, especially in old and severely ill patients intubated for acuterespiratory failure in the ICU. Specific bundles to prevent CVC may reduce morbidity and mortality related tointubation of these high-risk, critically ill patients. Trial registration : clinicaltrials.gov NCT01532063; registered 8 February 2012