To study the association between oppositional defiant disorder (ODD) and parenting style in children with attention deficit hyperactivity disorder (ADHD). A case-control study was performed on 482 children with ADHD, among whom 322 did not have ODD (simple ADHD group) and 160 had ODD (ADHD+ODD group). General demographic data and the Parenting Style Scale assessment scores were collected from the two groups. A multivariate logistic regression analysis was used to identify the association between parenting style and ODD in children with ADHD. There was no significant difference in parenting style scores (including rejection factor, emotional warmth factor, overprotection factor, and preference factor) and general demographic data between the simple ADHD and ADHD+ODD groups (P>0.05). Among the children with the predominantly inattentive type of ADHD, the older the child or the lower the father's educational level, the higher the risk of ODD (P<0.05), while there was no significant association between parenting style and the development of ODD (P>0.05). Parenting style is not significantly associated with the development of ODD in children with ADHD. In clinical practice, it is necessary to eliminate the stereotype that the parents of children with ADHD and comorbid ODD have a poor parenting style and look for the causes of development of ODD from multiple perspectives, so as to provide reasonable intervention recommendations.