<p>To assess the knowledge, attitude, and practice (KAP) of family members regarding <i>Mycoplasma pneumoniae</i> infection in children. This cross-sectional study collected demographic data and KAP scores from family members of children with <i>M. pneumoniae</i> infection at the People’s Hospital of Dongxihu, Wuhan, from March to July 2024. A total of 521 family members participated in this study. The average age of family members was 37.65 ± 7.27 years, and the average age of children was 6.60 ± 3.64 years. The average scores were 8.88 ± 4.52 for knowledge (possible range: 0–20), 33.07 ± 3.72 for attitude (possible range: 8–40), and 35.22 ± 4.28 for practice (possible range: 8–40). Positive correlations were observed among the KAP dimensions, with knowledge showing a strong correlation with both attitude (<i>r</i> = 0.189, <i>P</i> &lt; 0.001) and practice (<i>r</i> = 0.569, <i>P</i> &lt; 0.001). The structural equation model demonstrated that knowledge had a total effect on both attitude (β = 0.415, 95%CI 0.327–0.501, <i>P</i> = 0.009) and practice (β = 0.430, 95%CI 0.353–0.502, <i>P</i> = 0.007). Additionally, the attitude had a direct effect on practice (β = 0.680, 95%CI 0.567–0.747, <i>P</i> = 0.020). The indirect effect of knowledge on practice through attitude was also significant (β = 0.282, 95%CI 0.227–0.351, <i>P</i> = 0.007). Family members showed positive attitudes but lacked knowledge about <i>M. pneumoniae</i> infection, highlighting the need for targeted educational efforts. The results imply that improving knowledge about <i>M. pneumoniae</i> infection should also improve attitude and practice, possibly resulting in better patient outcomes.</p>