<h4>Background</h4>This full-scale confirmatory study aimed to measure serum neutrophil extracellular traps (NETs) levels in children with severe Mycoplasma pneumoniae pneumonia (SMPP) and non-severe MPP, and to compare the predictive performance of serum NETs, C-reactive protein (CRP), and lactate dehydrogenase (LDH) for SMPP.<h4>Methods</h4>A total of 200 children hospitalized with MPP between January 2023 and August 2024 were consecutively enrolled and divided into SMPP (n = 100) and non-severe MPP (n = 100) groups. This evidence concerns the gene CRP and Mycoplasma pneumoniae pneumonia.