Aim To investigate the relationship between plasma homocysteine levels and acute ischemic stroke in young people in Xinjiang. Methods A total of 186 young patients with acute ischemic stroke who were hospitalized in the Department of Neurology, the First Affiliated Hospital of Xinjiang Medical University from January 2019 to December 2020 were selected as the observation group. A total of 180 patients with non-cardiovascular and cerebrovascular diseases who were hospitalized during the same period were randomly selected as the control group. The patients in the observation group were divided into mild neurological impairment group, moderate neurological impairment group and severe neurological impairment group according to the National Institutes of Health Stroke Scale score at admission. According to the carotid intima-media thickness, they were divided into normal intima group, intimal thickening group, plaque formation group and carotid artery stenosis group. According to the modified Rankin scale score at 14 days, the patients were divided into a short-term good prognosis group and a short-term poor prognosis group. The clinical data and laboratory results of each group were compared. Risk factors for ischemic stroke, carotid atherosclerosis, and short-term poor prognosis were explored in young adults. Results The blood homocysteine level was significantly higher in young patients with acute ischemic stroke than that in the control group (P＜0.05). The risk of acute ischemic stroke in young people increased with the level of homocysteine, and the two groups of patients with moderate and severe neurological impairment had higher blood homocysteine levels than those with mild neurological impairment patients (P＜0.05). Homocysteine was a risk factor for carotid atherosclerosis (OR=34.4,5%CI:8.184～142.876) and short-term poor prognosis (OR=388.7,5%CI:50.271～3 003.108) in young patients with acute ischemic stroke. The area under the curve of homocysteine for predicting the short-term poor prognosis of acute ischemic stroke in young people was 0.712 (95%CI:0.616～0.807), and the area under the curve when it was combined with leukocytes was 0.831 (95%CI:0.745～0.916). Conclusions High plasma homocysteine level is a risk factor for acute ischemic stroke, carotid atherosclerosis and short-term poor prognosis in young people in Xinjiang. It has a certain predictive value for the short-term poor prognosis of young patients with acute ischemic stroke.