〔Abstract〕 Objective To explore the hemorrhagic transformation(HT) and its effect on prognosis in patients with acute ischemic stroke(AIS) after mechanical thrombectomy(MT). Methods A total of 114 patients with AIS received MT were enrolled. The modified Rankin Scale was used to evaluate the clinical outcome at 90 days of onset(0-2 points were good prognosis; 3-6 points were poor prognosis). The patients were divided into HT group(n=25) and non-HT group(n=89) according to their HT conditions. Binomial Logistic regression analysis was performed to determine the vascular risk factors of HT after MT and the effect of HT on prognosis. Results Among 114 patients, there were 25 cases of HT and 89 cases of non HT. The proportion of patients with diabetes in HT group was significantly higher than that in non-HT group. The NIHSS score of HT group at discharge was significantly higher than that in non-HT group. The proportion with good prognosis at 90 days in HT group was significantly lower than that in non-HT group(allP<0.05). Binomial Logistic regression analysis showed that diabetes, high levels of cholesterol and smoking were the major vascular risk factors for HT after thrombectomy(allP<0.05). HT was an important factor affecting the poor prognosis after arterial thrombectomy(P=0.026). Conclusion Diabetes, high levels of cholesterol and smoking are the main risk factors of HT after MT for AIS. HT is an independent risk factor for poor prognosis after MT.