Objective To explore the association between procalcitonin (PCT) level and the development of malignant brain edema (MBE) after acute cerebral infarction. Methods The data on patients with stroke admitted to the Department of Neurology of West China Hospital, Sichuan University between January 1, 2017 and December 31, 2018 were retrospective collected. Patients were divided into MBE group and non-MBE group based on whether MBE had occurred. The basic information and neuroimaging data of two groups of patients were compared and analyzed. Results A total of 798 patients were included. Among them, there were 93 cases of MBE (11.65%) and 705 cases of non-MBE (88.35%). The median time of MBE occurrence (lower quartile, upper quartile) was 29 (24, 54) hours after onset. The difference in the National Institutes of Health Stroke Scale, large-scale middle cerebral artery infarction, dysarthria, low fever, consciousness status, chronic heart failure, TOAST typing, mechanical ventilation, gastric tube placement, PCT on the first and third day of admission between the two groups were statistically significant (P<0.05). There was no statistically significant difference in the other indicators between the two groups (P>0.05). The results of multivariate logistic regression analysis showed that both day 1 PCT and large-scale middle cerebral artery infarction were associated with MBE. Conclusions Elevated PCT within 24 hours from onset is independently associated with the development of MBE after acute cerebral infarction. Patients with elevated PCT after cerebral infarction may require careful clinical management.