To assess the knowledge, attitude, and practice (KAP) of family members regarding Mycoplasma pneumoniae infection in children. This cross-sectional study collected demographic data and KAP scores from family members of children with M. pneumoniae 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 (r = 0.189, P < 0.001) and practice (r = 0.569, P < 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, P = 0.009) and practice (β = 0.430, 95%CI 0.353-0.502, P = 0.007). Additionally, the attitude had a direct effect on practice (β = 0.680, 95%CI 0.567-0.747, P = 0.020). The indirect effect of knowledge on practice through attitude was also significant (β = 0.282, 95%CI 0.227-0.351, P = 0.007). Family members showed positive attitudes but lacked knowledge about M. pneumoniae infection, highlighting the need for targeted educational efforts. The results imply that improving knowledge about M. pneumoniae infection should also improve attitude and practice, possibly resulting in better patient outcomes.