Warfarin-related traumatic intracerebral hemorrhage (ICH) is often fatal, yet timely evaluation and treatment can improve outcomes. Our study describes the process of developing and implementing a protocol to guide the care of patients with traumatic brain injury (TBI) on preinjury warfarin developed by nurses across several service lines at our Level I trauma center over a 6-month period. Further, we evaluated its efficacy by examining records of adult patients with TBI on preinjury warfarin admitted 1 year before and after protocol implementation. Efficacy was defined as activation rates, receipt and time to head computed tomography (CT) scan and international normalization ratio (INR), and receipt and time to fresh frozen plasma (FFP) administration in patients with ICH with an INR more than 1.5, as per protocol. A subset analysis examined patients with and without an ICH. Outcomes were compared using univariate analyses. One hundred seventy-eight patients were included in the study; 90 (50.6%) were admitted before and 88 (49.4%) after implementation. After implementation, there were improvements in activation rates (34.4% vs. 65.9%; p < .001), the frequency of head CT scans (55.6% vs. 83.0%; p < .001), time to INR (24.0 min vs. 15.0 min; p < .05), and, for patients with ICH with an INR 1.5 or more, decreased time to FFP (157.0 vs. 90.5; p < .05). In conclusion, our protocol led to a more efficient process of care for patients with TBI on warfarin. We believe the implementation process, managed by a dedicated group of nurses across several service lines, substantially contributed to the success of the protocol.