Objective To investigate the value of fluid attented inversion recovery （FLAIR） hyperintense vessel sign （HVS） on magnetic resonance imaging （MRI） in evaluating the prognosis of patients with acute cerebral infarction of the middle cerebral artery （MCA） after intravenous thrombolysis. Methods A retrospective analysis was performed for the clinical and imaging data of 60 patients with acute cerebral infarction who underwent multimodal magnetic resonance before intravenous thrombolysis. The patients were divided into HVS-positive group （group A with 25 patients） and HVS-negative group （group B with 35 patients）， and clinical features， radiological features， and prognosis were compared between the two groups. Results There were no significant differences between the two groups in the time from disease onset to MRI examination， the time from MRI examination to intravenous thrombolysis， and hemorrhagic transformation rate （P>0.05）. Compared with group B， group A had higher scores of the National Institutes of Health Stroke Scale （14.14±3.57 vs 10.00±3.43；P<0.001）on admission. Group A had a significantly higher proportion of patients with proximal large vessel occlusion compared with group B （84.0% vs 14.3%； P<0.001）. Compared with group B during follow-up at 3 months after thrombolytic therapy， group A had a significantly higher modified Rankin Scale score than group B （2.80±0.87 vs 1.94±0.97； P=0.001）. Conclusions HVS-positive patients with acute cerebral infarction tend to have poor prognosis at 3 months after intravenous thrombolysis， and proximal large vessel occlusion is closely associated with HVS. The presence of HSV may suggest poor prognosis after intravenous thrombolysis.