Background: Emergency medical technicians (EMT) typically perform endotracheal intubation (ETI) and administer epinephrine for out-of-hospital cardiac arrest (OHCA) patients. However, the clinical effectiveness of these procedures is still controversial, especially in regards to neurological outcomes in patients subsequently receiving intensive care after hospitalization. Study Objectives: The aim of this study was to evaluate the effectiveness of ETI and epinephrine administration in the pre-hospital setting on neurological outcomes following OHCA. Methods: This was a multicenter retrospective cohort study in Japan from January 2012 to February 2013. We used data from the Survey of Survivors after Cardiac Arrest in the Kanto Area in 2012 (SOS-KANTO 2012) database. Collected variables included age, gender, witnessed status, bystander CPR, first documented rhythm, hospital arrival time, and type of ICU care received after admission. To address selection bias, those who had early return of spontaneous circulation (ROSC) without ETI and epinephrine were excluded. Multivariate logistic regression was performed to investigate the association between EMT interventions and 1) hospitalization with ROSC, 2) 7-day survival, and 3) favorable neurological outcome, defined as 1-month cerebral performance category score of 1 or 2. Results: Of 6,019 OHCAs, 5,111 met the inclusion criteria (male, 57%; mean age, 71 years). 932 patients (18%) underwent ETI and 251 patients (4.9%) received epinephrine. 1,062 patients (20.8%) were hospitalized after ROSC. Multivariate logistic regression showed that OHCA patients who received pre-hospital epinephrine had a higher rate of hospital admission after ROSC (odds ratio [OR]=1.63, 95% confidence interval [CI] 1.35-1.97, P<0.001). However, they demonstrated poorer neurological outcomes (OR=0.31, 95%CI 0.12-0.82, P=0.02). OHCA patients undergoing pre-hospital ETI did not demonstrate significantly different outcomes. Conclusion: These findings suggest that pre-hospital procedures may not be necessary for increasing favorable neurological outcomes.