Changes in heart rate variability (HRV) and electroencephalographic (EEG) background are promising tools for risk stratification and outcome prediction in children seen in the Emergency Department (ED). Novel monitoring technologies offer an opportunity for determining the clinical value of these physiologic variables, however, studies evaluating these measurements obtained in the Pediatric ED are sparse. The current study used a single center, prospective, observational cohort study of HRV and EEG as early predictors of outcome in children with acute trauma. ECG and HRV data were successfully collected in 167 subjects and simultaneous collection of ECG and EEG data using a wireless monitoring device was piloted in 17 patients with 15 patients having EEG data rated as appropriate for clinical interpretation. The mean time from ED arrival to ECG and EEG recording start was 7.5 (SD 11.6) and 34.5 (SD 15.5) minutes, respectively. The mean time required for EEG electrode placement was 9.3 min (SD 5.8 min). Results showed recording early HRV and EEG is feasible in children with acute injury seen in the ED. This study suggests that high consent rates are possible with the adequate research infrastructure and physiologic variables may offer an early, non-invasive marker for injury stratification and prognosis in children.