The study aimed to identify biomarkers of azithromycin resistance (AZM) in patients infected with Mycoplasma pneumoniae by analysis of serum exosomes. Serum exosomes were isolated from AZM-sensitive and -resistant patients before and after treatment and analyzed by liquid chromatography and mass spectrometry. The results showed different protein expression patterns between these groups, with HIF-1 and IL-17 signaling pathways associated with AZM resistance. Four proteins – KCTD12, LTF, TF and MPO – were identified as potential biomarkers of resistance. These biomarkers achieved more than 80% sensitivity and 73.33% specificity in distinguishing responders and non-responders to AZM treatment. The results suggest that these biomarkers may serve as diagnostic tools for the early identification of azithromycin resistance in patients with M. pneumoniae infection. Further research should validate these biomarkers in larger groups of patients and explore their clinical utility.