Purpose: This study aimed to evaluate the efficacy of Parent-Child Interaction Therapy (PCIT) in Chinese children with attention-deficit/hyperactivity disorder (ADHD) or ADHD features. Methods: This study adopted a randomized controlled trial design without blinding. Participants were randomized into either the intervention group (n = 32) and offered PCIT by trained PCIT practitioners or the waitlist control group (n = 32) and offered PCIT after the intervention group had completed treatment. Parent participants were requested to complete questionnaires on their children's behavior and their parental stress. PCIT practitioners observed parent-child interactions according to a coding system. Results: Analysis was by intention to treat. The results indicated a significant decrease in child behavior and attention problems, parental stress, and negative parenting practices and an increase in positive parenting practices in the intervention group at postintervention (p = 0.002 in all cases). Conclusion: This study provided promising evidence on the effectiveness of PCIT in Chinese children with ADHD or ADHD features.