Background: Coronary artery lesions (CALs) are known to be the main complication in children with Kawasaki disease (KD). Instead of intravenous immunoglobulin (IVIG), corticosteroid therapy has been accepted to be used for children with KD who are unresponsive to IVIG. This study aimed to evaluate risk factors for CALs in children with KD. Methods: We retrospectively reviewed the clinical records of 2331 children with KD from January 2005 to December 2014. To identify the independent risk factors for CALs, multivariable logistic regression models were constructed using significant variables identified from univariate logistic regression analysis. Results: The incidence of CALs was 36.0% (840 of 2331), including 625 (26.8%) coronary artery dilations and 215 (9.2%) coronary artery aneurysms (CAAs). Multivariable logistic regression analysis identified that male, incomplete KD, longer fever duration, and C-reactive protein (CRP) 100 mg/L were independent risk factors for coronary artery dilatations. On the other hand, male, incomplete KD, longer fever duration, prolonged days of illness at the initial treatment, corticosteroid therapy, sodium %133 mmol/L, and albumin 35 g/L were the independent risk factors for CAAs. In addition, corticosteroid therapy, prolonged days of illness at the initial treatment, and albumin 35 g/L were the independent risk factors for giant CAAs. Conclusions: CALs might be associated with male sex, incomplete KD, longer fever duration, prolonged days of illness at the initial treatment, albumin 35 g/L, sodium %133 mmol/L, CRP 100 mg/L, and corticosteroid therapy. Corticosteroid therapy was an independent risk factor for CAAs and giant CAAs. Thus, corticosteroids should be used with caution in the treatment of KD with the risk for CALs.