Background and aims: Extension of hemorrhage after traumatic brain injury is a significant cause of secondary injury in the pediatric population. A thromboelastograph (TEG) is a functional assay that may offer advantages in assessment of coagulation compared to standard quantitative assays. Aims: We hypothesized that TEG parameters would reveal abnormalities in patients with normal standard coagulation testing. Methods: In an IRB-approved, prospective observational study, TEG was obtained within 2 hours of admission on pediatric ICU patients with evidence of intracranial hemorrhage on CT scan or a GCS < 12 on admission. A second TEG was obtained at 24 hours when IV access was available. Injury mechanism, demographics, GCS, TEG parameters, PT, PTT, INR, hemoglobin, were recorded. Results: Of 26 patients recruited, 16 patients had mild TBI, 2 had moderate TBI and 6 had severe TBI. Mechanism included 13 falls (50%), 3 abusive head injuries (11%), and 4 vehicle-associated injuries (15%). Of 2 hour samples (N=25), 16 (62%) exhibited some abnormality in quantified TEG parameters, while 19 (73%) were abnormal. Only 3 (12%) patients had quantitative abnormalities of PT, PTT, or INR at 2 hours after admission. PTT correlated with TEG parameters (p<0.05 for all). Fibrinogen correlated with K, Angle, MA, G, and A values (p<0.05). Evidence of enzymatic hypercoagulability was present in mildly injured patients (61%). Non-survivors (N=2) had higher PTT as well as higher R, higher K, lower Angle, and shorter MA and G reflecting a coagulopathic state (p< 0.01). Conclusions: Nonsurvivors of brain injury had confirmatory evidence of coagulopathy based on TEG. TEG parameters correlated with PTT and fibrinogen.