Stroke is one of the major causes of morbidity and mortality throughout the world. Research is going on to find out the factors which are associated with the severity of acute ischemic stroke. One of the factors which has gained interest in the field of research in recent time is serum ferritin. Serum ferritin is an acute phase reactant. It is recently under research as a marker of severity and prognosis of acute ischemic stroke. The aim of this study was to assess the relation of serum ferritin level with the severity of acute ischemic stroke. This cross-sectional study was conducted in the Department of Medicine in Mymensingh Medical College Hospital, Bangladesh from June 2020 to March 2023. In this study, 323 patients with acute ischemic stroke were enrolled. The severity of neurological disability was evaluated in all participants using National Institute of Health stroke scale (NIHSS) within 48 hours of onset of stroke. Blood was taken for estimation of serum ferritin levels within 48 hours of admission. In this study, mean serum ferritin level was 208.3±161.1 ng/ml in patients with acute ischemic stroke. The study showed most of the participants with high serum ferritin level had severe stroke (n=57, 77.0%; p<0.001). A statistically significant correlation was found between NIHSS and serum ferritin levels in acute ischemic stroke patients (r=0.71). This study revealed that serum ferritin level is associated with severity of neurological disability among patients with acute ischemic stroke. Further studies are required to establish the role of serum ferritin as a prognostic marker of acute ischemic stroke.