Background <p>We aimed to determine cut-off values of factors affecting early neurological improvement in patients after recombinant tissue plasminogen activator therapy for acute ischemic stroke.</p> Methods <p>A total of 135 patients with acute ischemic stroke treated with tissue plasminogen activator within 4.5 h of stroke onset were enrolled at a single center. Therapy outcomes were based on early neurological improvement, defined as when the NIHSS score after 24 h of tPA treatment decreased by ≥ 40% from the baseline value. Binary logistic regression analysis was used to identify the factors affecting early neurological improvement.</p> Results <p>Sixty-nine (51.1%) patients had early neurological improvement. Multivariate analysis showed that younger age, absence of diabetes mellitus, presence of hypertension, lower serum homocysteine (odds ratio, 0.865; 95% confidence interval, 0.787–0.950; <i>P = </i>0.003) and lower high-sensitivity C-reactive protein (0.345; 0.203–0.586; <i>P &lt; </i>0.001) levels were significantly associated with a higher probability of early neurological improvement. The cut-off values of serum homocysteine and high-sensitivity C-reactive protein were 11.99umol/L and 1.16mg/L, respectively. If Hcy and hsCRP were combined and used together, it was possible to predict ENI better than when Hcy and hsCRP was used alone. (sensitivity 92.75, specificity 60.61, and optimal cut-off value 23.65) ROC analyses showed modest discrimination for homocysteine (AUC 0.743, 95% CI 0.660–0.814) and hsCRP (AUC 0.747, 95% CI 0.665–0.818), with improved discrimination when both biomarkers were combined (AUC 0.797, 95% CI 0.719–0.861).</p> Conclusions <p>In IVT-treated AIS, lower homocysteine and hsCRP were independently associated with early neurological improvement.</p>