Introduction: With a Canadian aging population, the prevalence of mild traumatic brain injury (mTBI) among elderly is increasing and the age criterion of the Canadian CT head rule (CCHR) is challenged by many emergency physicians. We evaluated if increasing the age criterion of the CCHR would maintain its validity. Methods: We conducted an historical cohort study using the medical charts of all patients 65 years old or more who consulted at a Level One Trauma Centre emergency department (ED) for a mTBI between 2010 and 2014. The main outcome measures were clinically important brain injury (CIBI) on Computed Tomography (CT) and the presence of the CCHR criteria. The clinical and radiological data collection was standardized. Univariate analysis was performed to measure the predictive capacities of modified age cut-offs at 70 and 75 years old. Results: Out of the 104 confirmed mTBI in this study, 32 (30,8%) had CIBI on CT scan. Sensitivity and specificity [C.I. 95%] of the CCHR were 100% [89.1 - 100] and 0% [0.0 5.0] for an age criterion of 65 years old and above; 100% [89.1 - 100] and 4,2% [0.9 11.7] for a modified criterion of 70 years old; 100% [89.1 - 100] and 13,9% [6.9 24.1] for 75 years old. Furthermore, for an age criterion of 80 and 85 years old, sensitivity was respectively 90,6% [75.0 98.0] and 75,0% [56.6 88.5]. Conclusion: In our cohort, increasing the age criterion of the CCHR for minor head injury to 75 years old would benefit ED by further reducing CT scans without missing CIBI. A larger prospective study is indicated to confirm the proposed modification.