The National Institutes of Health Stroke Scale (NIHSS) is indispensable for both prognosis and treatment in patients with acute ischemic stroke. However, there is subtype of acute ischemic stroke (i.e., posterior circulation stroke) that is difficult to diagnose using the NIHSS. The authors report the limits of NIHSS in this stroke subtype, suggesting thereby the need to modify and render it more appropriate for the evaluation of the neurological signs occurring in posterior circulation stroke.