Background:Sparse published data are available regarding the prognostic importance of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with acute ischemic stroke.Materials and Methods:We prospectively studied 74 consecutive patients presenting with acute ischemic stroke within 24 hours of onset. All of them underwent laboratory and imaging evaluation and were treated as per guidelines. In all subjects, plasma NT-proBNP levels were measured at initial admission and again on day 7.Results:Their mean age was 54 ± 13.5years; there were 49 males; 18 (24%) patients died during the hospital stay. A statistically significant negative correlation between log NT-proBNP and Glasgow coma scale (GCS) score (P < 0.001); and a significant positive correlation between log NT-proBNP and National Institutes of Health Stroke Scale (NIHSS) score (P < 0.001) were observed. Baseline log NT-proBNP levels were higher among non-survivors compared with survivors (6.7 ± 0.47 vs. 5.37 ± 0.62; P = 0.06); day 7 log NT-proBNP levels were significantly higher in non-survivors compared with survivors (7.3 ± 0.26 vs. 4.5 ± 0.4; P = 0.000). In survivors, there was a statistically significant decline in log NT-proBNP levels from baseline to day 7 (5.3710 ± 0.620 vs. 4.5320 ± 0.451; P < 0.001). In contrast, among non-survivors, log NT-proBNP levels showed a statistically significant increase from baseline to day 7 (4.5322 ± 0.451 vs. 7.2992 ± 0.263; P < 0.001). On receiver operator characteristic curve (ROC) analysis, at a cut-off value of ≥ 6.0661, log NT-proBNP had a sensitivity and specificity of 98.2 and 88.9, respectively, in predicting death.Conclusions:Plasma log NT-pro-BNP level appears to be a useful biological marker for predicting in-hospital mortality inpatients presenting with acute ischemic stroke.