Stroke is a neurological syndrome consisting of signs or symptoms and loss of function of the focal (or global) in central nervous system and growing rapidly (within seconds or minutes). These symptoms lasted more than 24 hours or leading to death. Body temperature affects the condition of the body and affect the pathophysiology of systemic blood circulation and cerebral blood flow. The purpose of this study was to determine the relationship of body temperature to the severity of stroke in patients with acute ischemic stroke in the General Hospital of dr. Zainoel Abidin. This study was conducted by analytic methodology with cross-sectional design. Sampling was done by consecutive sampling as many as 52 samples. The research was conducted by taking the data and assess the patient's status through a questionnaire of NIHSS to check the severity of stroke. Data were analyzed by using univariate and bivariate methods. Bivariate method used Spearman's test with a confidence interval of 95% and α= 0,05. The results of the study indicate that there is a relationship between body temperature with the severity of stroke in patients with acute ischemic stroke in the General Hospital of dr. Zainoel Abidin with p= 0,005 and correlation between body temperature with the severity of stroke was weak with r= 0,384. Keywords: Body Temperature, Stroke Severity, Acute Ischemic Stroke, NIHSS