Objective: The objective of this study was to examine the association between delta V and risk of injury to children involved in frontal motor vehicle crashes. Background: Previous studies, primarily focused on adult occupants, have demonstrated the relationship between crash severity, as measured by delta V and injury severity. As children have unique safety needs, these results cannot be directly applied to the pediatric population. Methods: Case series crash investigation data and clinical injury information were reviewed from a child-focused crash surveillance system. Analyses were performed examining the relationship between the estimated delta V and any AIS >= 2 or any AIS >= 3 injury. Results: Detailed crash investigation and clinical data were available on 407 children involved in 235 frontal crashes. The average delta V for all crashes was 29 +/- 16.9 kph [18 +/- 10.5 mph (range, 5-123 kph)]. Delta V was strongly and positively associated with the odds of both an AIS >= 2 and AIS >= 3 injury (P = 2 injury increased on average by 56% (95% confidence interval [CI], 33%-85%) for each 10 kph increase in delta V. Similarly, the adjusted odds of at least one AIS >= 3 injury increased on average by 67% (95% CI, 40%-102%) for each 10 kph increase in delta V. The delta V at which 50% of child occupants would be expected to sustain any AIS >= 2 injury was 37 kph [23.0 mph (95% CI, 32-45 kph)], and any AIS >= 3 injury was 63 kph [39.1 mph (95% CI, 51-[infinity] kph)]. Conclusion: Delta V is strongly predictive of injury risk for child occupants. As many newer generation cars are now fitted with event data recorders, this information is increasingly available and may become useful as a clinical predictor. (C) 2006 Lippincott Williams & Wilkins, Inc.