BackgroundMycoplasma pneumoniae pneumonia (MPP) is responsible for 20 to 40% of all cases of pneumonia acquired by children and shows an increasing incidence year by year. The aim of this study was to investigate the expression of miR-34a in children with MPP and its diagnostic value, and further explore the relationship between miR-34a and the rehabilitation effect of children with MPP.MethodsThe expression level of miR-34a was detected by RT-qPCR, and the clinical value of miR-34a was analyzed by ROC analysis. In addition, the levels of IL-6, IL-18 and TNF-α in serum of children with MPP were detected by ELISA kit, and the correlation with miR-34a was analyzed.ResultsElevated levels of miR-34a were observed in the serum of children with MPP, and significantly higher expression levels were observed in children with severe symptoms and poor rehabilitation. The study suggested that miR-34a has potential as a diagnostic marker for MPP in children, helping to distinguish between mild and severe cases and predicting rehabilitation from MPP in children. In addition, miR-34a expression was positively correlated with IL-6, IL-8, and TNF-α levels.ConclusionsmiR-34a is closely related to MPP in children and miR-34a may be used as a clinical biomarker for MPP in children.