During posttraumatic amnesia (PTA), confusion, attention deficits, impaired memory, disorientation, and inability to process external stimuli often preclude accurate assessment of subtle neurologic changes. The Orientation Group Monitoring System (OGMS) has proven to be a simple, useful strategy for assessing cognitive status. Retrospective analysis of weekly aggregate OGMS scores indicated that a decline in performance of 0.23 or greater is clinically significant. Over a one-year period, 27 patients demonstrated significant decrements in OGMS performance, and in 93% of these instances, the decrease was attributable to a medical problem. Adverse effects of medication was the most common etiology of decreased performance (n = 13). Overwhelmingly, the decline in the OGMS score was the first indication of impaired cognition. This monitoring device is therefore useful as an indicator during PTA of declining cognitive function, warranting further medical evaluation.