There is growing concern about the frequency of computed tomographic (CT) scans performed for evaluation of adults with suspected mild traumatic brain injury. The Canadian CT Head Rule and the New Orleans Criteria are the most studied head CT decision tools that aid providers in determining which patients do not require a CT scan. This article examines recent research to determine which of these tools has proven to be the most effective at safely reducing the use of head CT scans. The reviewed studies concluded that both the Canadian CT Head Rule and the New Orleans Criteria had similar sensitivities, but the Canadian CT Head Rule showed superior specificity in predicting the presence of a clinically significant brain injury. The authors of this article recommend that the Canadian CT Head Rule be used in the evaluation of minor head injury to reduce unnecessary CT scans.