Background: The management of blood pressure (BP) for acute ischemic stroke (AIS) patients undergoing thrombolysis is still under debate. The purpose of this study was (1) to explore the association between post-thrombolysis BP and functional outcome and (2) to examine whether post-thrombolysis BP can predict functional outcome in Chinese AIS patients undergoing thrombolysis therapy. Methods: From December 2012 to November 2016, AIS patients undergoing thrombolysis were reviewed retrospectively in the Department of Neurology at Xuanwu Hospital. The BP levels were measured before and immediately after thrombolysis. Clinical outcomes, which comprised favorable outcome (modified Rankin Scale score 0-2) and unfavorable outcome (modified Rankin Scale score 3-6) at 3 months, were analyzed by logistic regression model. A receiver operating characteristic curve was used to evaluate the predictive value of post-thrombolysis BP. Results: Patients with unfavorable outcome at 3 months had a higher post-thrombolysis systolic BP than those with favorable outcome (P = .015). Multivariate analysis showed that post-thrombolysis systolic BP below 159.5 mm Hg was associated with favorable outcome. According to the receiver operating characteristic curve, post-thrombolysis systolic BP was a predictor of functional outcome with an area under the curve of .573 (95% confidence interval = .504-.642). Conclusions: Our study indicated that post-thrombolysis systolic BP is a predictor of functional outcome for Chinese AIS patients undergoing thrombolysis therapy. It is reasonable for AIS patients to keep post-thrombolysis systolic BP below 159.5 mm Hg to obtain a favorable outcome.