Motor vehicle crashes are a leading cause of death both in the United States and around the world. While research has showed younger females are at increased risk of fatality in fatal crashes, the underlying cause of this disparity is unclear. Data from the Fatality Analysis Reporting System (FARS), Mortality Multiple Cause of Death (MCOD), and National Automotive Sampling System Crashworthiness Data System (NASS-CDS) were used with the double-pair comparison method to identify relative risk of head injury and injury to other major body systems in motor vehicle crashes. FARS cases were linked to detailed cause of death records in MCOD. Young female occupants are at increased risk of fatal and severe head and abdominal injuries in motor vehicle crashes. This increased risk is pronounced for young females in both fatal crashes and non-fatal crashes with severe injuries. Along with previous research pointing to an increased overall fatality risk for young females in fatal crashes, these findings suggest a need to more carefully study biomechanical sex differences in car crashes.