Resuscitation 2015 Dec 19;99:63-71. Abstract More than two failed intubation attempts and failed endotracheal intubations (ETIs) are associated with severe complications and death. The aim of this review was to determine the number of ETIs a health care provider in training needs to perform to achieve proficiency within two attempts. A systematic search of the literature was conducted covering the time frame of January 1990 through July 2014. We identified 13 studies with a total of 1462 students who had attempted to intubate 19,108 patients. This review shows that in mostly elective circumstances, at least 50 ETIs with no more than two intubation attempts need to be performed to reach a success rate of at least 90%. However, the evidence is heterogeneous, and the incidence of difficult airways in non-elective settings is up to 20 times higher compared to elective settings. Taking this factor into account, training should include a variety of exposures and should probably exceed 50 ETIs to successfully serve the most vulnerable patients.