Available evidence suggests there is no difference in mortality between transfer and direct admissions. However, the significant heterogeneity across studies precludes deriving any definitive conclusions regarding the impact of interhospital transfer on mortality after major trauma. Moreover, most studies excluded patients dying at outlying hospitals, which may underestimate the association of transfer status with mortality. Prospective studies that address the limitations of the current evidence, including use of population-based trauma registries, are warranted to establish whether the process of interhospital transfer to higher level care when compared with direct admission to a trauma center negatively impacts clinical outcomes for trauma patients.