Abusive head trauma (AHT) is a leading cause of death in infants and toddlers. The objective of this study was to conduct an age-stratified comparison between children with AHT and accidental Traumatic brain injury TBI (aTBI) in the Approaches and Decisions in Acute Pediatric Traumatic Brain Injury (ADAPT) data. Children with severe TBI and an intracranial pressure monitor placed at a study site in the United States were enrolled from February 1, 2014, to September 31, 2017, and subjects <5 years of age and admitted to a US site were selected for analysis. Subjects were stratified by mechanism ('definite' or 'probable' concern for AHT classified as AHT; 'possible' or 'no' concern for AHT as aTBI) and age (<1 year, 1-2.9-years-, 3-4.9-years). Clinical data including epidemiological, clinical events, and imaging that occurred before monitor placement were compared. Of the 313 subjects (n = 111 AHT), apnea, seizures, and bilateral fixed pupils were more frequently observed in AHT (35.1% vs. 21.8%, = 0.01; 43.2% vs. 20.8, < 0.001; 31.5% vs. 15.8%, = 0.008). Subdural hemorrhages, midline shift, and ischemia were more frequently observed in AHT (96.4% vs. 73.1%, < 0.001; 54.1% vs. 35.0%, = 0.001; 40.9% vs. 12.2%, < 0.001) while contusion, subarachnoid hemorrhage and diffuse axonal injury were less frequently observed (20.2% vs. 49.7%; 38.5% vs. 58.4%; 3.7% vs. 20.8%, all < 0.001). Among the patients <1 year-old, there was no difference in apnea and seizures between AHT and aTBI (40.6% vs. 34.3%, = 0.53; 44.9% vs. 40.0%, = 0.63) while ischemia was more commonly observed in AHT (47.1% vs. 20.0%, < 0.001). AHT subjects exhibited unique clinical characteristics and radiological findings compared to aTBI, even after this age-stratified comparison. Further study is needed on the effects of both guidelines-based and novel therapies for this vulnerable and unique patient population.