Introduction : Although cardiac injury was reported in patients with neurosurgical conditions, few data reported cardiac injury in patients with traumatic brain injury (TBI).Objectives : The aim of this work is to report the incidence of cardiac injury in patients with TBI and its impact on patient outcome.Methods : A prospective observational study was conducted on a cohort of 50 patients with severe TBI. Only Patients with isolated severe TBI defined as Glascow coma scale (GCS) < 8 were included in the study. APACHE II score, GCS, hemodynamic data, serum Troponin I, electrocardiogram (ECG), echocardiographic examination, and patients' outcome were recorded. A Cardiac Injury Score (CIS) was calculated for all patients (elevated troponin = 1, abnormal echocardiography defined as ejection fraction <55% and/or regional wall motion abnormalities = 1, hypotension = 1), univariate and multivariate analysis for risk factors for mortality was done for all risk factors.Results: Among a cohort of 50 patients, age was 31±12, APACHE II was 21±5, and male patients were 45 (90%). Troponin I was elevated in 27(54%) patients, abnormal echocardiography and hypotension were documented in 15(30%) and 16 (32%) patients respectively. The in hospital mortality was 64%. Risk factors for mortality by univariate analysis were; age, GCS, APACHE II score, serum troponin level, CIS, and hypotension. However, in multivariate analysis the only three independent risk factors for mortality; were APACHE II score (OR=1.25, 95% confidence interval: 1.021.54, P=0.03) and, score (OR=8.38, 95% confidence interval: 1.4448.74, P=0.018) and GCS (OR=0.18, 95% confidence interval: 0.041-0.869, p=0.032)Conclusions : Cardiac injury is common in patients with TBI and associated with increased mortality. The association of high cardiac injury score and poor outcome in these patients’ warrants further larger study.