Background: Blood pressure variability (BPV) is a predictor of short- and long-term disability in patients with acute ischemic stroke (AIS). Its effect on more immediate functional outcomes has been seldom studied, and the results are inconsistent. We aimed to determine the role of BPV during the first 5 days of hospitalization in functional status at the time of discharge of patients with AIS.Methods: We enrolled 134 patients diagnosed with AIS and BPV using standard deviation and coefficient of variation (CV %). These were associated with the dichotomized modified Rankin Scale at discharge using logistic regression. Results: Patients with unfavorable outcomes were significantly older (P=0.014), had a lower body mass index (P=0.001), were less likely to present with dyslipidemia (P=0.001), had lower serum triglyceride levels (P=0.012), had a longer hospitalization period (P<0.001), and had a higher mean National Institutes of Health Stroke Scale score at admission (P<0.001). After adjusting for multiple confounders, the CV % of systolic blood pressure (SBP) in the first 120 hours after admission had a significant effect on functional disability at discharge. Conclusion: Variability in SBP in the first 5 days of hospitalization had a deleterious effect on the functional outcomes at discharge of patients with AIS. The role of diabolic blood pressure variability seems to be significant only in the first 24 hours of admission; however, further research is required.