Background: Previous studies have shown that macrophage migration inhibitory factor (MIF) is involved in the pathogenesis of asthma. This study aimed to investigate whether serum MIF reflects a therapeutic response in allergic asthma. Methods: We enrolled 30 asthmatic patients with mild-to-moderate exacerbations and 20 healthy controls, analyzing the parameter levels of serum MIF, serum total immunoglobulin E (tIgE), peripheral blood eosinophil percentage (EOS％), and fractional exhaled nitric oxide (FeNO). Lung function indices were used to identify disease severity and therapeutic response. Results:Our study showed that all measured parameters in patients were at higher levels than those of controls. After one week of treatment, most parameter levels decreased significantly except for serum tIgE. Furthermore, we found that serum MIF positively correlated with EOS％ as well as FeNO, but negatively correlated with lung function indices. Receiver operator characteristic (ROC) curve analysis indicated that among the parameters, serum MIF exhibited a higher capacity to evaluate therapeutic response. The area under the curve (AUC) of MIF was 0.931, with a sensitivity of 0.967 and a specificity of 0.800. Conclusions:Our results suggested that serum MIF may serve as a potential biomarker for evaluating therapeutic response in allergic asthma with mild-to-moderate exacerbations.