Aim To investigate the expression levels of serum microRNA-124 (miR-124) and microRNA-182 (miR-182) in acute cerebral infarction (ACI) and the value in the combined diagnosis and prognosis of ACI. Methods 120 patients with ACI were enrolled as the observation group, and 80 healthy subjects were used as healthy controls.According to the brain infarct volume, patients of the observation group were divided into small infarction group(＜5 cm³), middle infarction group (≥5 cm³ and ≤10 cm³) and large infarction group (＞10 cm³). The relative expression levels of serum miR-124 and miR-182 were measured in all enrolled patients, and the value of combined diagnosis was analyzed by receiver operating characteristic curve (ROC curve). ACI patients were followed up for one year, and the prognosis of the combined positive and negative groups was analyzed. Results The relative expressions of serum miR-124 and miR-182 in ACI patients were (2.63±0.59) and (2.69±0.69), respectively, which were significantly higher than those in the control group((1.08±0.32) and (1.07±0.46))(P<0.05). The relative expression of miR-124 in the middle and large infarction group was significantly lower than that in the small infarction group (P<0.05). The relative expression of miR-182 in the middle and large infarction group was significantly higher than that in the small infarction group (P<0.05). Pearson correlation analysis showed that the relative expression of miR-124 was negatively correlated with brain infarct volume (r=－0.613, P<0.01), and the relative expression of miR-182 was positively correlated with brain infarct volume (r=0.761, P<0.01). When miR-124 was cut off by 1.34, the sensitivity of diagnosis of ACI was 73.33%, the specificity was 90.00%, the area under the curve was 0.775 (95%CI 0.715～0.834, P=0.030); when miR-182 was cut off by 1.45, the sensitivity of diagnosis of ACI was 66.67%, the specificity was 87.50%, the area under the curve was 0.675 (95%CI 0.602～0.749, P=0.038); the sensitivity of combined diagnosis was 88.33%, the specificity was 86.25%, and the area under the curve was 0.811 (95%CI 0.756～0.866, P=0.028). The area under the combined detection ROC was significantly higher than that of the single test (P<0.05). The follow-up prognosis found that the patients with positive diagnosis had significantly higher mortality at 8 months and 12 months after treatment than those with negative diagnosis (P<0.05). Conclusion miR-124 and miR-182 are highly expressed in the serum of patients with ACI. The combination of the two is of great value in the diagnosis and prognosis evaluation of ACI.